taxonID	type	description	language	source
0E3EF64DFFB58507FF26F8FEFF19FF40.taxon	materials_examined	TYPE: — ECUADOR. Guayas: El Oro, Hda. Daucay, 500 m, 23 Apr 1944, Cornejo & Bonifaz 2531 (holotype: K, illustration of type in Luer (2009) as Fig. 30!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB58507FF26F8FEFF19FF40.taxon	distribution	Distribution: — Ecuador. Notes: — Luer (2009) described the narrow, needle-like leaves of this species as unique in the genus. However, similar leaves are now also known to be found in M. sotoanus, described in 2010 (Fig. 6 G). This species is similar to M. scandens and M. pennellius, but M. aciculifolius is distinguished by the long-ciliate margins of the middle lobe of the lip.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FEF4FC88FB84.taxon	materials_examined	TYPE: — PERU. Dept. of San Martín: lithophytic, Province of Chachapoyas, 1835, Mathews 1899 (holotype: K!). Homotypic synonym: Humboltia affinis (Lindl.) Kuntze (1891: 667), as “ Humboldtia ”. Heterotypic synonyms: Pleurothallis rigidifolia Reichenbach (1855 b: 224). Humboltia rigidifolia (Rchb. f.) Kuntze (1891: 668), as “ Humboldtia ”. TYPE: — PERU. San Martín: lithophytic near Chachapoyas, 1840, Mathews 3187 (holotype: G!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FEF4FC88FB84.taxon	materials_examined	TYPE: — ECUADOR. Morona Santiago: Andes east of Sigsig, 1887, Lehmann 6511 (holotype: K!; isotype: AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FEF4FC88FB84.taxon	distribution	Distribution: — Costa Rica, Colombia, Ecuador, Peru and Bolivia. Notes: — The illustration of M. affinis in Luer (1992) based on a plant collected in Ecuador is similar to that presented here in Fig. 12 A, also from Ecuador. However, the type of M. affinis was collected in Peru. As indicated by Luer and demonstrated by several of his sketches at SEL, this species is highly variable. The material of M. affinis recently described and illustrated from Costa Rica (Rojas-Alvarado & Karremans 2017) is clearly similar to some of Luer’s drawing of this species, but also similar to some of Luer’s drawings of M. dasyllis (all at SEL). Some differences between the diverse material are evident, with specimens from Costa Rica being morphologically more consistent with the type specimen of P. furfuracea than with that M. affinis. It is possible that more than one species is currently treated under the name M. affinis, but with the available information it is impossible to separate these entities. Specimens from the type locality of M. affinis in Peru and M. dasyllis in Ecuador need to be examined carefully, and a thorough study of the variation of this species across its distribution is needed.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FBB8FE2BFA39.taxon	materials_examined	TYPE: — ECUADOR. Zamora-Chinchipe: Cordillera del Condor, epiphytic in forest east of Los Encuentros, 1650 m, 21 Jan 1989, Luer et al. 14035 (holotype: MO!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FBB8FE2BFA39.taxon	distribution	Distribution: — Ecuador and Peru. Notes: — This species is frequently misidentified as M. fimbriatus (and vice versa), but M. antennifer has nonprolific ramicauls (vs. prolific ones), a lip with a conspicuous longitudinal pair of apical keels and conspicuously dentate midlobe margins (vs. lip with a longitudinal pair of low keels in the middle and a midlobe minutely dentate at the apex, frequently apiculate).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FA2CFB41F8AD.taxon	materials_examined	TYPE: BOLIVIA. Cochabamba: Prov. Carrasco, Parque Nacional Carrasco, 20 km entrando de Monte Punco a Pajcha, cerca al túnel Hidroeléctrica Ivirizu, 17 º 27 ’ 16 ” S, 65 º 16 ’ 33 ” W, 2100 m, bosque montano pluvial, ladera empinada, 8 Jan 2019, Zárate 6551 & Bayá (holotype: BOLV!; isotype: LPB!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48507FF26FA2CFB41F8AD.taxon	distribution	Distribution: — Bolivia. Notes: — This recently described species has the proliferous habit and flowers similar to M. epibator, from which it differs in the longer sepals (5.5 – 6.0) with slender tails (vs. 4.5 mm and clavate), lip yellowish suffused with purple (vs. lip dark purple) with a prominent erect callus at the base (vs. lacking a tall basal callus).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48500FF26F8A1FA92FAC5.taxon	materials_examined	TYPE: — VENEZUELA. “ Caracas ”: 6000 ft., flowered in cultivation by Schiller in Hamburg, Wagener s. n (holotype: W!). Homotypic synonym: Humboltia ceratothallis (Rchb. f.) Kuntze (1891: 667), as “ Humboldtia ”. Heterotypic synonyms: Pleurothallis longipes Körnicke (1855: 281). TYPE: — [VENEZUELA]. Wagener s. n. (holotype, lost). Dubois-reymondia lancipetala Karsten (1858: 47). Pleurothallis lancipetala (H. Karst.) Schlechter (1919: 62). Myoxanthus lancipetalus (H. Karst.) Luer (1982 a: 43). TYPE: — [VENEZUELA]. Crescit cum sequente in montibus Venezuelanis, 2000 ‒ 2500 metra altis pronvinciae Caracas, cultivated at Allard´s, Garden, Karsten s. n.? (holotype: lost, lectotype here designated, (colour illustration) tab. XLVII, in Florae Columbiae 1: 95. 1858 (Fig. 13).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB48500FF26F8A1FA92FAC5.taxon	distribution	Distribution: — Venezuela, Colombia, Ecuador and Peru. Notes: — Pleurothallis ceratothallis was described by Reichenbach (1854) from a plant collected in Caracas, Venezuela, and cultivated in Hamburg by Consul Schiller. In 1855, Körnicke described the same species from a plant sent from Venezuela by Wagener and cultivated in the garden of Mr. Allard. Only a few years later, in 1858, the same species was given a third name by Karsten, who described and illustrated this species as Dubois-reymondia lancipetala, also from a plant brought from Caracas and cultivated at the garden of Mr. Allard, according to the protologue. In his monograph of Myoxanthus, Luer (1992) indicated “ H. Wagener 1073 ” as the collection number of the type of P. ceratothallis. According to the introduction of Reichenbach´s article dedicated to the orchids collected by Wagener, it is clear that the type of P. ceratothallis was collected by Wagener. However, no indication of Wagener’s number 1073 is given either in the protologue or on the type at W, but instead there is a label on the sheet annotated as “ ceratothallis Schiller L 611 ”. Luer may have taken the number “ 1073 ” from the Schiller´s catalogue of 1861 where the name P. ceratothallis appears under the number 1071. However, this is simply a numbered series in Schiller´s catalogue, not the collector’s number. A similar number is found on the type of Pleurothallis hystrix (W- 0117999), “ L 612 Pleurothallis hystrix ”, and the type of Pleurothallis loranthophylla Reichenbach (1852: 674, W- 0075649!), which has two handwritten labels, “ Pleurothallis loranthophylla Kalbreyer Dec. 57. L 562 ” and “ 148 Rhynchopera punctata Wagener ”. We do not know what the numbers with “ L ” stand for, but these numbers could be by Reichenbach’s and the collectors. Since the holotype of Dubois-reymondia lancipetala has not been found and may have been destroyed in the Berlin Herbarium during World War II (Merrill 1943; Hermann Karsten was professor of botany in Berlin from 1856 – 1868), the beautiful and detailed painting of the type plant in life included in the original publication (Karsten 1858) is designated here as the lectotype (right) of D. lancipetala. The illustration of D. lancipetala that appeared together with that of D. palpigera (≡ M. reymondii) was both drawn while flowering in cultivation in the garden of a Mr. Allard, leaving no doubt about its relationship to Pleurothallis ceratothallis. Pleurothallis longipes, which fits with P. ceratothallis, is also in need of a typification. However, we have located no original material. Myoxanthus ceratothallis is similar to M. hirsuticaulis, M. parvilabius and M. priapus in having yellowish and purple-striped flowers with small trichomes adaxially on the sepals. However, it is recognized by the margin sepals covered by trichomes to the apex and reflexed synsepal with conspicuous adaxial, white trichomes at the base.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB38501FF26FA79FC9DF828.taxon	materials_examined	TYPE: — COSTA RICA. Cartago: Agua Caliente, Lankester 358 (holotype: K, photo of type, illustration of type, AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB38501FF26FA79FC9DF828.taxon	distribution	Distribution: — Costa Rica and Panama. Notes: — Pleurothallis cerea has been commonly placed under the synonymy of M. octomeriae or M. congestus. However, Luer noted differences between the two species, and in 1991 annotated a specimen collected by Endrés from Costa Rica as “ M. cereus (Ames) Luer ”, a combination that he never published. When Soto (2008) revised the taxonomy of the Mexican Myoxanthus, he reduced M. octomeriae, with all its synonyms, to the synonymy of the older M. congestus, a name based on material from Mexico. However, he also noted the odd features of P. cerea, especially in leaf size and shape and lip structure. After studying material of Pleurothallis cerea from Costa Rica, Rojas-Alvarado & Karremans (2017) formally recognized it as a species and transferred it to Myoxanthus. This Central American species is easily distinguished from the closely related M. octomerioides (Mexico), M. congestus (Mexico to Colombia-Venezuela) and M. pulvinatus (Peru and Brazil) by its broad, elliptic to ovate petiolate leaves, and oblong, conspicuously adaxially verrucose, frequently apiculate lip vs. narrow elliptic, sessile leaves and lip not apiculate of the other species (Rojas-Alvarado & Karremans 2017). FIGURE 12. Myoxanthus species. A – C. M. affinis. D. M. antennifer. E. M. ceratothallis. F. M. cereus. G. M. chloe. H – I. M. cimex. J – K. M. colothrix. L. M. conceicionensis. Photographs by: L. Grobler (A). L. E. Yupanqui (B). G. Rojas-Alvarado (C, J, K). A. Karremans (F, G). Ecuagenera (D). R. Parsons (E, L). S. Vieira-Uribe (H). H. R. Ellis (I).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FF60FC91FE60.taxon	materials_examined	TYPE: — BOLIVIA. Cochabamba: Chapre, epiphytic in cloud forest along the road to Tablas, alt. 2300 m, 9 Feb. 1980, Luer, Luer & Vásquez 5200 (holotype, SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FF60FC91FE60.taxon	distribution	Distribution: — Bolivia. Notes: — This Bolivian endemic may produce up to 2 m proliferous plants,. It is similar to M. frutex, which is also found in Bolivia. However, it is distinguished from the latter by its whitish flowers and acute lateral lip lobes vs. yellowish to brownish flowers and lip margins obscurely angled.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FDD4FBD7FC30.taxon	materials_examined	TYPE: — COLOMBIA. Risaralda: Mistrató, between Mistrató and San Antonio de Chamí, Mampay, 1700 m, collected by M. De Robledo, J. Posada & L. De Posada, flowered in cultivation by M. & O. Robledo at La Ceja, 25 Jan 1978, Luer 2321 (holotype: JAUM; isotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FDD4FBD7FC30.taxon	distribution	Distribution: — Colombia. Notes: — Myoxanthus cimex is similar to M. reymondii but has an acute dorsal sepal generally fully opened backwards, covering the ovary and pedicel vs. dorsal sepal generally obtuse, not completely opened, an ovate acute, apical petal callus vs. rounded callus and unlobed lip vs. small acute lateral lobes.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FC24FBD0FAC9.taxon	materials_examined	TYPE: — ECUADOR: Morona-Santiago: epiphytic in cloud forest east of Paute, 1700 m, 10 Jul 1977, cultivated at SEL- 77 - 2694, flowered in cult. 26 Mar 1981, Luer et al. 5991 (holotype: SEL!; isotype: AMES).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FC24FBD0FAC9.taxon	distribution	Distribution: — Costa Rica, Panama and Ecuador. Notes: — Myoxanthus colothrix is morphologically similar to M. parahybunensis, but the sheaths on the basal half of the ramicauls are completely covered with trichomes vs. smooth, and it has a toothed white column vs. untoothed with purple wings and white oblong lip with a pair of conspicuous longitudinal keels emerging near the middle on the disc vs. subpandurate lip with purple margins and microscopical keels on the disc.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FA82FDFFF936.taxon	materials_examined	TYPE: — BRAZIL. Espírito Santo: Conceição do Castelo, Cachoeira da Fumaça, 620 m, Jun 2003 (fleurs), Sanson s. n. ex Frey 531 (holotype: MBML!; isotype: LY).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB18502FF26FA82FDFFF936.taxon	distribution	Distribution: — Southeastern Brazil. Notes: — Myoxanthus conceicionensis is endemic to southeastern Brazil. It is most similar to M. punctatus but easily distinguished from the latter by purplish flowers vs. yellowish to brownish and purple stripped sepals vs. sepals with circular purple to dark red warts.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB1850CFF26F92EFE2EFDF4.taxon	materials_examined	TYPE: — MEXICO. Linden s. n. [W- 0079486!, drawing annotated by Richard and plant and flower fragment “ Flor. in hort. bot. Fac. Med. Par. Octubre 1842 ”, lectotype designated by Soto Arenas 2008: t. 1053; isolectotype, W- 0079482!]. Heterotypic synonyms: Pleurothallis octomeriae Schlechter (1922: 21). Myoxanthus octomeriae (Schltr.) Luer (1982 a: 47). TYPE: — PANAMA. Chiriquí: An Baumen in Schluchten, c. 5000, Powell 252 [holotype: B, destroyed; lectotype, AMES- 23789!, selected by Christenson (1991: 130); isolectotype MO- 950657!].	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB1850CFF26F92EFE2EFDF4.taxon	materials_examined	TYPE: — VENEZUELA. Without precise locality, Steyermark s. n. (holotype: AMES-spirit, illustration!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB1850CFF26F92EFE2EFDF4.taxon	distribution	Distribution: — Mexico, Guatemala, Belize, Honduras, Nicaragua, Costa Rica, Panama, Venezuela and Colombia. Notes: — This species is morphologically similar to M. cereus, M. octomerioides and M. pulvinatus. From M. cereus, M. congestus is distinguished by the narrow elliptic leaves vs. broad elliptic to ovate, ovate petals vs. oblong, scarcely adaxially verrucose lip with angled margins vs. oblong and conspicuously verrucose. From M. octomerioides, it is distinguished by the yellowish whitish perianth vs. perianth suffused with pink to purple. From M. pulvinatus and M. congestus, it differs in the column with aciculate teeth on each side and acute to obtuse lip vs. triangular, frequently bidentate on each side and generally apiculate lip. When Soto Arenas revised Mexican Myoxanthus, he noted that the original material of P. congesta fitted the concept of M. octomeriae better than that of M. octomerioides as previously stated by Luer (1982 a, 1992; see Rojas- Alvarado & Karremans 2020 for an extended discussion). Pleurothallis ramentacea, described from Venezuela by Garay & Dunsterville (1976), also fits the concept of P. congesta. See Incertae sedis at the end of this list of Myoxanthus species for a commentary of Pleurothallis elongata Klotzsch, which Rojas-Alvarado and Karremans (2020) included as a synonym of M. congestus.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FD68FDD0FB84.taxon	materials_examined	TYPE: — ECUADOR. Morona Santiago: Cordillera del Cutucú, between Mendez and Morona, 950 m, 17 Jan 1989, Luer et al. 13971 (holotype: MO!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FD68FDD0FB84.taxon	distribution	Distribution: — Ecuador. Notes: — According to Luer & Hirtz (1992), the flowers of this species are distinguished by their densely redspiculate floral bracts, ovary and sepals that are borne by short peduncles (actually pseudopeduncles) usually less than three millimeters long, petals thickened and microscopically erose or cellular-capitate and ligulate lip with a pair or denticulate carinae. The most similar species is M. herzogii, which shares most of the same diagnostic features except for the denticulate carinae of the lip.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FBB8FDBAFA55.taxon	materials_examined	TYPE: — ECUADOR. Pastaza: epiphytic in tall forest 20 km east of Puyo, 1000 m, 28 Jul 1975, Luer et al. 479 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FBB8FDBAFA55.taxon	distribution	Distribution: — Ecuador. Notes: — This Ecuadorian endemic is recognized by the greenish perianth tinged with purple, revolute margins of the sepals, narrow, long, acute teeth at the column apex, a pair of rounded calli at the base of the column foot and a trilobed lip with ovate, oblique and erect lateral lobes, midlobe ovate, disc with a longitudinal pair of lamellae that meet on the midlobe and then diverge forming a glenium-like cavity. Superficially, it is somewhat similar to M. eumeces Luer (1982: 36) and M. fimbriatus.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FA08FDD6F8C8.taxon	materials_examined	TYPE: — COLOMBIA. Antioquia: without collection data, flowered in cultivation by R. Londoño near Medellín, 20 Mar 1989, Luer 14312 (holotype, MO!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850CFF26FA08FDD6F8C8.taxon	distribution	Distribution: — Colombia. Notes: — Myoxanthus epibator is endemic to Colombia and most similar to the recently described M. bolivianus from Chochabamba, Bolivia. The former is distinguished by the shorter clavate sepals, 4.5 mm long vs. sepals forming slender tails, 5.5 – 6.0 mm long and dark purple lip that lacks a tall basal callus vs. yellowish suffused with purple with a prominent erect callus at the base.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850DFF26F87CFBDCFE9D.taxon	materials_examined	TYPE: — ECUADOR. Zamora-Chinchipe: epiphytic in cloud forest at the pass between Loja and Zamora, 2700 m, 11 Feb 1978, Luer et al. 2530 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBF850DFF26F87CFBDCFE9D.taxon	distribution	Distribution: — Ecuador. Notes: — This species is endemic to high mountains of Zamora Chinchipe of southeastern Ecuador. It is caespitose with slender ramicauls that are longer than the leaves, similar to M. hirsuticaulis.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FED0FCF3FCDC.taxon	materials_examined	TYPE: — VENEZUELA. Aragua: near Colonia Továr, Fendler 1490 (holotype: K!; isotype: K!; GH!). Heterotypic synonym.: Pleurothallis speciosa Luer (1977: 392 – 393). Myoxanthus speciosus (Luer) Luer (1982: 51). TYPE: — PANAMA. Chiriquí: epiphytic in cloud forest above Guadalupe, ca. 2000 m, 13 Sep 1976, flowered in cultivation 5 Feb 1977, Luer & Butcher 1371 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FED0FCF3FCDC.taxon	distribution	Distribution: — Guatemala, El Salvador, Costa Rica, Panama, Colombia, Venezuela and Peru. Notes: — Myoxanthus exasperatus was recently found to apply to what had been previously known as M. speciosus (Rojas-Alvarado & Karremans 2020, also see commentary under M. parahybunensis). This species is easily distinguished by its caespitose habit, fully hispidulous sheaths, the ramicaul and narrow ovate leaves frequently purple suffused, flowers yellowish striped with red-purple, a column without teeth and an oblong purple-suffused lip with two longitudinal, rounded calli from the base to above the middle.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FC90FAC2FB35.taxon	materials_examined	TYPE: — ECUADOR. Napo: Cotundo, 1100 m, collected by A. Hirtz, flowered in cultivation in Quito, 18 Mar 1985, Hirtz 2245 (holotype: MO!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FC90FAC2FB35.taxon	distribution	Distribution: — Ecuador, Peru. Notes: — This proliferous species with purplish flowers is similar to the also proliferous M. scandens and the nonproliferous M. antennifer. It is recognized by acuminate lateral sepals vs. acute in M. scandens and M. antennifer and the fimbriate margin of the petals vs. margins shortly ciliate in M. scandens and entire in M. antennifer.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FB31FBDFF92C.taxon	materials_examined	TYPE: — BOLIVIA. La Paz: Sud Yungas, terrestrial in humus-rich rocky soil, near Unduavi, 3200 m, Nov 1910, Buchtien 2613 (holotype: assumed to have been destroyed in the bombing of the Berlin herbarium; lectotype, designated here: K- 000583610!; isolectotypes, AMES!, L!, US).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26FB31FBDFF92C.taxon	distribution	Distribution: — Bolivia and Peru. Notes: — This species generally produces huge, erect or pendent, pseudo-terrestrial proliferous plants. It is similar to M. chloe, which is also found in Bolivia. However, it can be distinguished from that species by the yellowish to brownish flowers and obscurely angled lip margins vs. whitish flowers and acute lateral lobes of the lip. In the protologue of M. frutex, Schlechter (1912) did not indicate where the holotype was preserved. Assuming the holotype was in Berlin and was lost when the herbarium was destroyed, Luer (1992) indicated the location of a type at K, but he did not designate it explicitly as a lectotype. We thus make this designation here.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26F929FCD0F7B4.taxon	materials_examined	TYPE: — ECUADOR. Morona Santiago: epiphytic in felled trees, 30 km south of Gualaquiza, 500 m, 6 Aug 1975, Luer, Luer & Wilhelm 451 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBE850DFF26F929FCD0F7B4.taxon	distribution	Distribution: — Ecuador. Notes: — This Ecuadorean species is easily recognized by the caespitose plants with ramicauls covered by long hispidulous sheaths, purple flowers, obovate petals in the basal half then contracted and acute and trilobate lip with oblique, rounded, erect lateral lobes and apiculate midlobe.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850EFF26FF60FD65FD11.taxon	materials_examined	TYPE: — ECUADOR. Morona-Santiago: epiphytic in the forest north of Gualaquiza, 1500 m, Mar 1982, collected by Luer & Andreetta, flowered in cultivation 14 Mar. 1983, Luer 8693 (holotype: SEL-spirit!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850EFF26FF60FD65FD11.taxon	distribution	Distribution: — Ecuador. Notes: — Luer distinguished M. gorgon from M. monophyllus by its shorter perianth and “ peduncle ” (actually the pseudopeduncle) and yellowish perianth versus whitish. However, both species have short pseudopeduncles, similar colour of the flowers, a floral bract covering the base of the perianth, petals with dentate margins and similar column, lip and plant habits. The most obvious difference between the two species is the length of the perianth, as mentioned and illustrated by Luer, but the reflexed sepals on M. gorgon are also noteworthy. There is significant variation in length and colour of the perianth of M. monophyllus (Fig. 14 F – H), and both entities have highly overlapping distributions. We think it is necessary to document the variation of these two taxa across their ranges to determine if M. gorgon can be consistently distinguished from M. monophyllus.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850EFF26FD44FB8BFAA4.taxon	materials_examined	TYPE: — BOLIVIA. La Paz: Sud Yungas, epiphytic in scrub vegetation near Unduavi, 3200 m, 28 Jan. 1980, Luer et al. 4975 (holotype: SEL!; isotype: K!). Heterotypic synonym: Pleurothallis frutex var. robusta Schweinfurt (1951: 91). TYPE: — PERU. Cuzco: Paucartambo, Pillahuata, epiphytic in forest on mountain crest, 3400 m, 11 Dec 1942, Vargas 3007 (holotype: AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850EFF26FD44FB8BFAA4.taxon	distribution	Distribution: — Bolivia and Peru. Notes: — This species was first described as Pleurothallis frutex var. robusta by Schweinfurt in 1951, a variety distinguished by the more robust plant with strictly few-branched stems, commonly much longer leaves, different coloured flowers and lip with a relatively larger anterior portion. However, the description fits M. gyas, and it is included as synonym by Luer in 1982. The huge proliferous M. gyas is similar to M. chloe and M. frutex, both with the same habit. Myoxanthus gyas is recognized by the rose, reddish or brownish spotted flowers vs. whitish in M. chloe and yellowish in M. frutex, and longer petals, 25 mm vs. 10 mm in M. chloe and 11 mm in M. frutex. Luer (1992) indicated that M. gyas is also distinguished from M. frutex by the habit producing only one stout superposed ramicaul after the other, but the first species may sequentially produce up to four superposed ramicauls.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850FFF26FA98FF62F844.taxon	materials_examined	TYPE: — BOLIVIA. La Paz: forest along Río Sanjana (San Juan), 3000 m, Oct 1911, Herzog 2423 [holotype: lectotype, designated by Luer (1994): S!; isolectotype: L!). Heterotypic synonym: Myoxanthus affinoides Luer (1983 a: 385). TYPE: — ECUADOR. Zamora-Chinchope: epiphytic in forest south of the pass south of Yangana, 2600 m, 3 Mar 1982, Luer et al. 7114 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBD850FFF26FA98FF62F844.taxon	distribution	Distribution: — Bolivia, Ecuador, Peru. Notes: — Luer (1982) included M. herzogii as synonym of M. ceratothallis because Schlechter’s description and illustration could apply to the latter. However, at that time Luer had not inspected the type of the M. herzogii because its location was unknown. In 1994, after locating original material of Pleurothallis herzogii at the Stockholm Herbarium (S), Luer realized that it is conspecific with M. affinoides, a species he had described in 1983 from Ecuador and different from M. ceratothallis. Myoxanthus herzogii is similar to M. affinis, but the former is distinguished by its shortly pseudo-pedunculate flowers with abaxially dense, shortly pubescent sepals and linear and thick above the middle petals (Luer 1994). On the lectotype of M. herzogii at S, a label by Garay reads: “ since the type does not exist in Berlin, this is chosen by me in my monograph ”. As far as we know, that lectotypification was never published. FIGURE 14. Myoxanthus species. A – B. M. congestus. C. M. ephelis. D. M. eumeces. E. M. exasperatus. F & G. M. fimbriatus. H. M. frutex. I. M. georgei. J. M. aff. gorgon. K. M. gyas. L. M. aff. herzogii. Photographs by: G. Rojas-Alvarado (A). N. de Jong (B). E. Schulz (C). G. Merino (D). S. Vieira-Uribe (E). Ecuagenera (F). R. Parsons (G). R. Repasky (H, K). R. Velázquez (I). A. Hirtz (J). L. E. Yupanqui (L).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FF60FCD7FE44.taxon	materials_examined	TYPE: — COSTA RICA. Cartago: vicinity of Pejivalle, ca. 900 m, 7 Feb 1926. Standley & Valerio 47052 (holotype: AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FF60FCD7FE44.taxon	distribution	Distribution: — Costa Rica, Panama, Colombia and Peru. Notes: — This species is recognized by the purple veined and mottled flowers with a suborbicular synsepal and purple lip with white fimbriate margins. Myoxanthus ortizianus and M. priapus are the only other species that have a suborbicular synsepal but not a lip with fimbriate margins.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FDF8FEB1FBFC.taxon	materials_examined	TYPE: — VENEZUELA. “ Caracas ”, Wagener L 612 (holotype: W!). Heterotypic Synonym: Pleurothallis lonchophylla Reichenbach (1886: 555). TYPE: — VENEZUELA. Without type locality, from a cultivated specimen (holotype, W).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FDF8FEB1FBFC.taxon	distribution	Distribution: — Colombia and Venezuela. Notes: — This and M. trachychlamys are the only species with an elongate rhizome. Flowers of M. hystrix are similar to those of M. melittanthus but differ mainly in shape of the petals and column. The petals of M. hystrix are subquadrate in the basal half with obtusely angled margins that contracts into a yellow distal half with a clavate tip downward oriented, whereas in those of M. melittanthus the contracted part is longer and narrower, forming a slender tail with a slightly clavate, generally upwardly oriented tip. The column wings of M. hystrix are lobulate and rounded, emerging from near the middle to the apex of the column, whereas in M. melittanthus they are broader, not lobulate, extending from the base to the apex of the column. Pleurothallis lonchophylla, described by Reichenbach (1866) from a cultivated plant without locality, definitely corresponds to M. hystrix; description of the habit and flowers are compatible with both.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FB70FB18F8C8.taxon	materials_examined	TYPE: — BRAZIL. Minas Geraes: Les capoes des champs de la serra de Caldas, Feb, Barbosa Rodrigues s. n. (holotype: lost, lectotype here designated, tab. 130, in Iconogr. Orchid. Bresil, vol. 3, at the Library of Rio de Janeiro Botanical Garden, cited as tab. 436 (unpublished) in Barbosa Rodrigues. (1877: 35); copied and reproduced in black and white in Cogniaux (1896: tab. 117, fig. II) reproduced in colour in Sprunger et al. (1996, vol. 1: 189). Homotypic synonyms: Chaetocephala lonchophylla (Barb. Rodr.) Barbosa Rodrigues (1882: 39). Dubois-reymondia lonchophylla (Barb. Rodr.) Brieger (1977: 43). Pleurothallis lonchophylla (Barb. Rodr.) Cogniaux (1896: 589), nom. illeg. Heterotypic synonym: Pleurothallis warmingii Reichenbach (1881: 93). TYPE: — BRAZIL. Minas Geraës: epiphytic in forest at Lagoa Santa, Warming s. n. (holotype: K).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB8508FF26FB70FB18F8C8.taxon	distribution	Distribution: — Brazil. Notes: — The holotype of Myoxanthus lonchophyllus is lost, and the species is here lectotypified using an illustration associated with the original material. The species, like its relatives M. conceicionensis, M. punctatus and M. ruschii, is endemic to southern Brazil. They share the fleshy flowers frequently mottled or dotted with dark purple-red, petals with margins revolute, a fleshy lip with apical margins revolute, column with a pair of calli on the column foot and anther cap ciliate-fimbriate. However, M. lonchophyllus is easily recognized by the conspicuous fimbriate margins of the lip. Myoxanthus ruschii also has a ciliate to fimbriate lip, but only apically, and the petals are not revolute. The lip of M. punctatus may also have short fimbriate margins, but it is fleshier with the apex rounded.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB850AFF26F87CFC66FEF0.taxon	materials_examined	TYPE: — VENEZUELA. Táchira: Alto de Palo Grande above Palmira, Mejia s. n. (holotype: AMES!). FIGURE 15. Myoxanthus species. A. M. hirsuticaulis. B. M. hystrix. C. M. lonchophyllus. D. M. melittanthus. E. M. merae. F – H. M. monophyllus. I. M. montanus. J. M. octomerioides. K. M. oliviae. L. M. ortizianus. Photographs by: G. Rojas-Alvarado (A). R. Parsons (B, D, H, K). J. Gastin (C). L. E. Yupanqui (E, G). E. Hunt (F). P. Ortiz (I). P. Mannens (J). B. Coral Jaramillo (L).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFBB850AFF26F87CFC66FEF0.taxon	distribution	Distribution: — Venezuela. Notes: — This species has been collected only in the mountains of western Venezuela. The habit and large fleshy lip with the margins revolute to the apex and auricles at its base are similar to M. punctatus and its allies, whereas morphology of sepals, petals and column is more similar to M. reymondii. Myoxanthus mejiae is distinguished by petals with a clavate apex downwardly oriented, broadly rounded and decurved lip with a thickened apex with a pair of basal auricle, and a curved column with broad rounded apical wings.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850AFF26FE64FC26FBA0.taxon	materials_examined	TYPE: — COLOMBIA. Nariño: epiphytic, 10 km northwest of Pasto, Daza, 3000 m, Jan 1922, Hopp 136 (holotype: B, destroyed, neotype here designated, Luer et al. 3023, SEL- 021582!; isoneotype, SEL- 021538!, illustrated in Luer (1982: Fig. 8; 1992: pl. 22). COLOMBIA. Cauca: Páramo de Barbilla, 3070 m, 27 Jul 1978.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850AFF26FE64FC26FBA0.taxon	distribution	Distribution: — Colombia and Venezuela. Notes: — Myoxanthus melittanthus is similar to M. hystrix, but the former differs mainly in petals and column shape. Those of M. melittanthus are transversally rhomboid in the lower third with rounded margins, then contracted forming a slender tail with a slightly clavate tip, generally upwardly oriented, whereas those of M. hystrix are subcuadrate in the basal half with the margins obtusely angle, then contracted but terete into a yellow apex with a clavate tip downward oriented. The column wings of M. melittanthus are broader, not lobulate, extending from the base to the apex of the column, whereas in M. hystrix the wings are lobulate and rounded, emerging from near the middle to the apex of the column. The holotype of this species was probably destroyed during the WWII. A neotype is designated here based on a collection by Luer near the type locality because no material associated with the protologue has been found. Carnevali and Ramírez (1988 – 1989) mentioned that Venezuelan plants of M. melittanthus differ from those in Colombia in their slightly smaller flowers and glabrescent sepals that are verruculose adaxially.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850AFF26FB94FCFFF9E1.taxon	materials_examined	TYPE: — ECUADOR. Pastaza: epiphytic in forest east of Mera, 1000 m, 20 Mar 1976, Luer et al. 682 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850AFF26FB94FCFFF9E1.taxon	distribution	Distribution: — Ecuador and Peru. Notes: — Myoxanthus merae is a small, caespitose species with slender ramicauls and narrow leaves and producing successive single flowers. It can be recognized by the yellowish flowers with the red to yellowish sepals that are pubescent externally, basally ovate petals then narrower with revolute margins, a red-brownish elliptical, oblong lip, weakly trilobed, with lateral lobes erect below the middle, disc with a pair of longitudinal calli near the centre and a pair of small auricles at its truncate base. Myoxanthus simplicaulis from Venezuela and Guyana has a similar habit and flowers. However, the latter has wider petals with a more pronounced, narrow, thick apical section, more pronounced, oblique lateral lobes of the lip and a pair of longitudinal calli emerging below the middle that extend to the base. Myoxanthus merae had been previously recorded only from Ecuador, but the photograph reproduced here (Fig. 15 E) is from a plant collected in Tingo María National Park, Peru.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850BFF26F954FD28FF40.taxon	description	Homotypic synonyms: Pleurothallis poeppigii Lindley (1836: 354). Humboltia poeppigii (Lindl.) Kuntze (1891: 668), as “ Humboldtia ”. Pleurothallis myoxanthus Schlechter (1921: 141), nom. illeg. superfl.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850BFF26F954FD28FF40.taxon	materials_examined	TYPE: — PERU. Huanuco: common and epiphytic in the forests near Casapi, Feb, Poeppig, P. 1743 (holotype: W!; isotype: K!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB9850BFF26F954FD28FF40.taxon	distribution	Distribution: — Colombia, Ecuador and Peru. Notes: — Myoxanthus monophyllus is distinguished by its multiple congested flowers with long narrow sepals and petals and pubescent floral bract covering the pedicel, ovary and base of the perianth. Christenson (1995) reported an isotype of M. monophyllus at LE, which we have not seen. Myoxanthus gorgon is similar but with a shorter, reflexed perianth (see comments under M. gorgon for a comparison). Pleurothallis poeppigii Lindl. and P. myoxanthus Schltr. are replacement names based on M. monophyllus as clearly stated by their respective authors. The two names are therefore homotypic synonyms, the latter superfluous.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FEF4FB8BFC14.taxon	materials_examined	TYPE: — COLOMBIA. Cundinamarca: Guayabetal, “ Monterredondo ”, 1750 m, Aug 1977, Ortiz 937 (holotype: HPUJ!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FEF4FB8BFC14.taxon	distribution	Distribution: — Colombia. Notes: — The proliferous habit of this species is similar to M. frutex and M. gyas, but M. montanus differs by bearing congested white flowers with a pubescent floral bract covering the base of the perianth and lateral sepals connate to near the middle. 31. Myoxanthus neillii Luer & Dodson (1992: 62) TYPE: — ECUADOR. Napo: near Coca, 200 m, epiphytic in large fallen tree, collected by D. Neill, flowered in cultivation at the Río Palenque Science Center, 3 Oct 1986, Dodson 16621 (holotype: MO, not located, lectotype, here designated, illustration of the holotype in Luer (1992: pl. 25). Distribution: — Ecuador and Peru. Notes: — This species is similar to M. affinis and M. parahybunensis, but M. neillii is distinguished from these by its small flowers with sepals only 4 – 5 mm long, oblong petals not narrowed above the middle and column with teeth at the apex. Since the holotype at MO was not located, a lectotype is designated here.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FC48FB0BFA54.taxon	materials_examined	TYPE: — MEXICO. Without locality, cultivated by J. Wilmore of Oldford, England, collected by Henchman s. n. (holotype: K!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FC48FB0BFA54.taxon	distribution	Distribution: — Mexico. Notes: — The habit of this Mexican species is similar to that of M. congestus and M. pulvinatus in having ramicauls covered by whitish sheaths with scars of fallen trichomes and elliptic leaves. However, M. octomerioides is distinguished by having an ovary and perianth tinged with pink vs. yellowish to whitish and whitish flowers of M. congestus and M. pulvinatus, respectively, and segments of the flowers more oblong and do not open widely vs. segments more ovate that often open widely on the other species. Myoxanthus octomerioides is also similar to the Centro American M. cereus, both with oblong perianth segments that do not open widely, but the first is easily distinguished by its flowers tinged with pink vs. creamy and sessile leaves vs. petiolate leaves. See Incertae sedis at the end for commentary on Pleurothallis elongata Klotzsch, which Luer (1982) included as a synonym of M. octomerioides.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FA08FD90F8C8.taxon	materials_examined	TYPE: — PERU. Cuzco: Urubamba, 3100 m., 5 Dec 1968, Vargas 20860 (holotype: AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB8850BFF26FA08FD90F8C8.taxon	distribution	Distribution: — Peru. Notes: — Myoxanthus oliviae, described from Peru, was said to differ from M. serripetalus in the colour of flowers, brownish yellowish vs. dark-purple, an entire midlobe vs. fimbriate midlobe and apex of the petals sagittate vs. apex oblong to linear. According to our revision, the linear apex of the petals in M. serripetalus (and dark-purple flowers) appears to be consistent. However, the entire midlobe of the lip in M. oliviae and brownish flowers are inconsistent, but a fimbriate margin may also be found.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB88534FF26F87CFB2AFEF0.taxon	materials_examined	TYPE: — COLOMBIA. Putumayo: Valle del Sibundoy. Vereda San José del Chunga. ca. 2200 m. 19 Jan 2007, flowered in cultivation Mar 2007. ex cult. Medina T. 466 (holotype: HPUJ, MEDEL – photos!, UGDA – drawing!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFFB88534FF26F87CFB2AFEF0.taxon	distribution	Distribution: — Colombia. Notes: — Myoxanthus ortizianus is similar to M. priapus; they share the purple-yellow flowers covered abaxially with short trichomes, lateral sepals forming a suborbicular synsepal, petals yellowish purple-stripped, obovate to oblong basally, then contracted, and lip with a thick, erect basal callus. However, the former is distinguished by its narrower petal apex forming a slender tail vs. apex narrow not forming a slender tail, and a scarcely trilobed lip with rounded lateral lobes below the middle vs. lip oblong with small acute lateral lobes near the middle.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF878535FF26FE64FA84FDF4.taxon	materials_examined	TYPE: — PANAMA. Epiphytic along the El Llano-Carti road, 300 m, flowers greenish, cultivated at SEL, 4 Mar 1976, Luer et al. 1018 (holotype: MO!, illustration in Luer 1992 t. 34!). Similar to M. scandens but with greenish translucent sepals and petals vs. sepals dark purple and petals stripped with purple, the column sometimes suffused with purple vs. greenish; lip scarcely trilobed with a short bilobed convergent basal callus and a longitudinal pair of low rounded calli near the base extending to nearly the apex vs. lip with a longitudinal pair of conspicuous lamellar keels near the apex. Epiphytic, caespitose, proliferous herbs, up to 40 cm long. Roots fibrous, 1 mm in diameter, branching. Ramicauls cylindrical, flexible, 1 mm in diameter, up to 25 cm long, with up to 12 internodes, the basal ones shorter, producing up to 6 prolific stems at the apex enclosed by tubular, hispidulous sheaths. Sheaths acute, rusty coloured when young, covered by trichomes, imbricate, overlapping up to 5 mm the next internode, the uppermost generally covering the base of the leaves up to 1.5 cm. Leaves narrowly ovate to linear, conduplicate, acute, 3.0 – 11.0 × 0.2 – 0.5 cm, subpetiolate, narrowly cuneate basally, minutely tridentate, abscission layer evident. Inflorescence with a reduced peduncle, enclosed during early development by a 3 mm long spathe that frequently disintegrates when old, producing single-flowered coflorescences in succession. Pseudopeduncle 3 – 4 mm long, whitish with minute trichomes, subtended by a 1.0 – 2.5 mm long bract with trichomes to the apex. Floral bract 2.0 – 2.5 mm long, covered with minute trichomes. Pedicel 2.0 – 2.5 mm long, with a 1.0 mm long filament emerging at the apex. Ovary cylindrical, 1.5 ‒ 2.0 mm long, greenish, cellular glandular. Sepals and petals greenish, sometimes with purple spots. Dorsal sepal greenish translucent, ovate, acute 3.0 ‒ 4.5 × 1.5 mm, 5 - veined. Lateral sepals ovate, acute, 3.0 ‒ 3.5 × 1.5 – 2.0 mm, oblique, 4 - veined, connate at the base forming a mentum, sometimes with minute trichomes. Petals wider in their basal half, then gradually contracted into a thickened apex with serrulate margins, 3.0 – 3.5 mm long, 2.0 mm wide basally, triveined. Lip oblong, weakly trilobed, 1.5 – 2.0 × 1.0 mm, suffused with deep purple and yellowish in the middle, hinged to the column foot, apex retuse; lateral lobes erect near the middle, obtusely angled; the base subtruncate with an auricle on each side and a short bilobed convergent callus, the disc with a longitudinal pair of parallel, rounded calli extending from the near the base to near the apex, elevated in the middle. Column semiterete, sometimes suffused with purple, 2 mm long, winged, slightly arched, with an acicular to narrowly acute tooth on each side of the stigma, the clinandrium shortly irregular, dorsally elongate; the anther incumbent, the stigma ventral, column foot 1 mm long. Anther cap 0.5 mm wide, greenish, with purple at the apex. Pollinia two, yellow, obovoid, laterally flattened, 0.3 mm wide, with a pair of small, flat, white caudicles. Fruits capsular, ellipsoid, 7 × 5 mm, dry perianth persistent.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF878535FF26FE64FA84FDF4.taxon	etymology	Etymology: — Referring to the provenance of this species.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF878535FF26FE64FA84FDF4.taxon	distribution	Distribution: — Panama. Habitat and ecology: — Found from 50 – 600 m. It has been collected from Bocas del Toro to the west of Panama Province and recorded flowering all year round. Additional material examined: — PANAMA. Bocas del Toro: hill slope at Boca Chica creek, 5.8 km SE of the community Charco La Pava ,, 550 m, epiphyte on fallen branch, flowers yellow with purple spots, lip heavily spotted purple to dark purple, 21 Oct 2007, Laube et al. SL 545 (PMA, Fig. 17 A). Colon: Teck Cominco Petaquilla mining concession, forested slopes, epiphytic, perianth translucent white with purple markings, 100 m, 25 Jun 2008, McPherson 20659 (PMA); Donoso, Coclé del Norte, Cerca del Río Escribano, área del helicad BL 03, bosque húmedo tropical, 46 m, 24 Aug 2012, Martínez 972 (PMA); Donoso, Coclé del Norte, Área del helicad C 10, Bosque húmedo tropical, al borde del Río Belencillo, 104 m, 28 Aug 2012, Martínez 1034 (PMA). Cocle: La Pintada, Palmarazo Río San Juan, Parque Nacional G. D. Omar Torrijos H. Área de Calle Larguita (Palmarazo), bosque al norte del área de acampar, Río San Juan, epifita en árbol caído, flor blanca translucida, 180 m, 19 Jul 2013, Espinosa et al. 6153 (PMA). Panama: La Enedia, region of Cerro Jefe; epiphyte, flowers yellow-tan, sepal & petals flushed with red-purple, lip dark red-purple, Dressler 3303 (PMA); Region of Cerro Jefe, epiphyte in tree tops, flowers green flushed with rose-violet, lip dark purple, 15 Oct 1976, Dressler 3078 (MO); El Llano-Carti Road, 14 km north of Panamerican Highway, cloud forest; 350 - 500 m, epiphyte, 22 Jan 1977, Folsom & Kauke 1407 (MO): Llano-Cartí road, 1 mile past saw mill on dirt road, 300 - 500 m, sepals, petals, and column yellow with purple, lip, solid red purple, 11 Nov 1979, Todzia et al. 1023 (CR); El Llano-Carti Road, 300 m; epiphyte on tree fall; petals yellowish-clear, Km 12.4, 8 Nov 1984, de Nevers & Herrera 4230 (MO). Notes: — Plants of this species are almost indistinguishable from the prolific M. sotoanus and M. scandens, with which this species has been confused. However, M. panamense can be distinguished by its greenish translucent sepals vs. purple in M. scandens, brownish in M. sotoanus, petals transluscent greenish vs. purple stripped in M. scandens and translucent yellow in M. sotoanus and column sometimes suffused with purple vs. column yellowish green in the others. The lip is similar to that of M. scandens but differs in having a bilobed short, convergent small basal callus and disc with a longitudinal pair of rounded calli from near the base to near the apex vs. a small callus at the base becoming a pair of conspicuous longitudinal lamellae near the apex where the lamellae becomes frequently irregular. The lip of M. panamense is easily distinguished from that of M. sotoanus because in the former it is purple and weakly trilobed with obtusely angled lateral lobes vs. yellow and conspicuously trilobed with ovate and oblique lateral lobes.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868535FF26FD68FCFAFA54.taxon	materials_examined	TYPE: — BRAZIL. Minas Gerais: in trees along the River Parahybuna, 680 m, Barbosa Rodrigues s. n. (holotype: lost, lectotype selected in Rojas-Alvarado & Karremans 2020, tab. 150, in Iconogr. Orchid. Bresil, vol. 3, at the Library of Rio de Janeiro Botanical Garden, cited as tab. 789 [(unpublished) in Barbosa Rodrigues (1882: 76); copied and reproduced in black and white in Cogniaux [1896: tab. 111, fig. II, 1896]; reproduced in colour in Sprunger et al. (1996, vol. 1: 208). Heterotypic synonoyms: Pleurothallis peduncularis Lindley (1843: 47), nom. illeg. hom. non Hook. 1841. Humboltia peduncularis Kuntze (1891: 668), as “ Humboldtia ”, replacement name. Specklinia peduncularis Barros (1983 [1984]: 110), nom. illeg. TYPE: — BRAZIL. Without locality, imported from Rio de Janeiro by Messrs. Loddiges (holotype, K!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868535FF26FD68FCFAFA54.taxon	materials_examined	TYPE: — ECUADOR. San Nicolas: Río Pilaton, flowered in June 1886, Sodiro 30 [actually Luis Sodiro] (holotype: BR!; isotype, P!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868535FF26FD68FCFAFA54.taxon	distribution	Distribution: — Costa Rica, Venezuela, Colombia, Ecuador, Peru and Brazil. Notes: — Myoxanthus parahybunensis is the oldest available name for the taxon commonly referred to as M. exasperatus, a name that has been misapplied (Rojas-Alvarado & Karremans 2020, see Myoxanthus exasperatus discussion). Since Pleurothallis peduncularis Lindl. is illegitimate (according to Art. 58.1, Ex. 1 of the International Code of Nomenclature, Turland et al. 2018), the name must be cited as Humboltia peduncularis Kuntze. Myoxanthus parahybunensis is recognized by its caespitose habit, ramicauls with few trichomes covering only the basal sheath of the ramicaul, other ramicaul sheaths smooth without trichomes or scars, flowers yellowish and whitish with sepals and petals narrowly elongate, the column not toothed but with purple wings and lip subpandurate with purple margins. Myoxanthus parahybunensis is similar to M. neilli but distinguished by flowers up to 10 mm in diameter vs. 5 mm and purple margins of the lip vs. greenish.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868535FF26FA08FA86F8C8.taxon	materials_examined	TYPE: — GUYANA. Serra Acarai, epiphytic on low tree, on rocky hill top, east of Onoro, 2 Oct 1952, Forestry Dept. G 340 Record No. 7316 (holotype: NY!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868535FF26FA08FA86F8C8.taxon	distribution	Distribution: — Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela. Notes: — Myoxanthus parvilabius is similar to M. xiphion but easily distinguished by its caspitose, prolific habit vs. caespitose not prolific and purplish flowers vs. yellowish. This species is here reported for the first time from Colombia based on a plant collected in Santander (Gutiérrez Morales 64 & Moreno, JBB- 18745!, Fig. 17 D).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868530FF26F87CFCA7FDD9.taxon	materials_examined	TYPE: — ECUADOR. Pastaza: epiphytic in felled trees about 20 km east of Puyo, ca. 600 m, 28 Jul 1975, Luer et al. 687 (holotype: SELspirit; illustration in Luer 1976 b as f. 183!). FIGURE 17. Myoxanthus species. A. M. panamense. B – C. M. parahybuensis. D. M. parvilabius. E. M. pennellius. F. M. priapus. G. M. pulvinatus. H – J. M. punctatus. K – L. M. reymondii. Photographs by: L. Nauheimer (A). G. Rojas-Alvarado (B, C). S. Moreno (D). A. Hirtz (E). Y. Dewèvre (F). M. Rosim (G). J. Gastin (H). R. Stalder (I). L. F. Varella (J). R. Parsons (K). J. Riksen (L).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF868530FF26F87CFCA7FDD9.taxon	distribution	Distribution: — Ecuador and perhaps Peru (see below). Notes: — Pleurothallis pennellia was described from Ecuador on the basis of a specimen that flowered in cultivation at the Marie Selby Botanical Gardens (Luer 1976 b). Luer compared it with M. scandens, but described it as having a much less prolific plant. The plant that served as type of P. pennellia eventually became prolific in cultivation, just like specimens of M. scandens, prompting Luer (1992) to place it under the synonymy of that species (Luer 1992). However, based on the original description and illustration of the type, even with the prolific habit, M. pennellius is still easily distinguished from M. scandens. It differs from M. scandens in its sepals with an obtuse to rounded apex vs. acute, narrowly ovate petals slightly contracted above the middle, vs. wider basally then conspicuously contracted into a thickened apex and a lip with two longitudinal lamellae above the middle vs. with two longitudinal lamellae from the base to near the apex, a short clinandrium vs. long-hooded. None of the specimens of M. scandens studied here shares any of these features. We agree with Pupulin et al. (2010) that the photo of a Peruvian plant labelled M. scandens in Zelenko & Bermúdez (2008) fits the description of M. pennellius.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838530FF26FD8CFE5BFB84.taxon	materials_examined	TYPE: — ECUADOR. Loja: epiphytic in cloud forest east of Yangana, Altos de Numbala, 2800 - 2900 m, Jun 1982, D’Alessandro 195 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838530FF26FD8CFE5BFB84.taxon	distribution	Distribution: — Ecuador and Peru. Notes: — Myoxanthus priapus is similar to M. ortizianus with which it shares the purple-yellowish flowers covered abaxially by short trichomes with the lateral sepals forming a suborbicular synsepal and petals yellowish purple stripped, obovate to oblong basally, then contracted and lip with a thick erect callus near the base. It can be distinguished by the basal half of the petals oblong to obovate then narrow vs. apex of the petals narrower forming a slender tail and an oblong lip with small acute lateral lobes near the middle vs. lip weakly trilobed with rounded lateral lobes below the middle.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838530FF26FBB8FBB9F9E0.taxon	materials_examined	TYPE: — BRAZIL. Minaes Geraes: Serra das Bicas, Barbosa Rodrigues s. n. (holotype: lost, lectotype, here designated, tab. 144, in Iconogr. Orchid. Bresil, vol. 3, at the Library of Rio de Janeiro Botanical Garden, cited as tab. 803 [unpublished] in Barbosa Rodrigues (1882: 77); copied and reproduced in black and white in Cogniaux 1896: tab. 91, fig. III; reproduced in colour in Sprunger et al. (1996, vol. 1: 202).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838530FF26FBB8FBB9F9E0.taxon	distribution	Distribution: — Brazil and Peru. Notes: — This species had been previously known only from southeastern Brazil, but this species was recently documented from Tingo María National Park, Peru (Ocupa et al. 2017). Unfortunately, no herbarium specimens were prepared. The habit and flower of M. pulvinatus is similar to M. congestus but mainly distinguished by its column apex frequently bidentate on both sides and generally apiculate lip vs. with an acute tooth on both sides and apex acute to obtuse. Since the illustration cited by Barbosa Rodrigues in the original publication of A. pulvinata is the only remaining original material associated with this species, it is designated here as lectotype.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838531FF26F954FC6EFDD8.taxon	materials_examined	TYPE: — BRAZIL. Minas Geraes: epiphytic in dry forest along the river Parahybuna, 670 m, Barbosa Rodrigues s. n. (holotype: lost; lectotype, here designated, illustration tab. 131, in Iconogr. Orchid. Bresil, vol. 3, at the Library of Rio de Janeiro Botanical Garden, cited as tab. 802 (unpublished) in Barbosa Rodrigues (1882: 38); copied and reproduced in black and white in Cogniaux (1896: tab. 117, fig. I); reproduced in colour in Sprunger et al. (1996: vol. 1: 189). Pleurothallis seidelii Pabst (1975: 54). Myoxanthus seidelii (Pabst) Luer (1982: 51). TYPE: — BRAZIL. Espírito Santo: near Marechal Floriano, flowered in cultivation, 19 June 1973, Seidel 1068 (holotype, HB).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF838531FF26F954FC6EFDD8.taxon	distribution	Distribution: — Brazil. Notes: — Luer (1992) reduced M. seidelii to the synonymy of M. lonchophyllus. However, after an “ examination of fresh flowers from near the type-locality ”, he later considered the two taxa distinct on account of the sepals being “ pubescent within and the lip is bulbous at the apex ” (Luer 1997). Myoxanthus seidelii is clearly associated with M. lonchophyllus due to its apically hispidulous-spiculate lip, prominently featured in the original description and illustration. Here, M. seidelii is nonetheless considered conspecific with M. punctatus despite the apparent differences in the apical lobe of the lip. Even though the lip of fresh flowers of M. punctatus seem glabrous, with age and dehydration they become verrucose and in extreme cases spiculate. Examination of the type illustrations of both species, the description and illustrations provided in Luer (1997) and Chiron & Ximenes (2009) and other material attributed to these taxa show that one grades into the other. Other than the lip apex, we find no distinguishing features. As in the other species described by Barbosa Rodrigues for which the holotype has been lost, the illustration in his original publication of Chaetocephala punctata is here designated as lectotype.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828531FF26FD8CFA49FAC0.taxon	materials_examined	TYPE: — VENEZUELA. “ Caracas ”: forest of Petaquire, 6000 ft., 1 Dec. 1850, Wagener s. n. (holotype: W!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828531FF26FD8CFA49FAC0.taxon	distribution	Distribution: — Colombia, Ecuador and Venezuela. Notes: — Even though the genus Duboisia Karsten (1847: 394) is an illegitimate homonym, Duboisia reymondii is both valid and legitimate according to articles 23.4 and 55.1 (Turland et al. 2018). Additionally, when Duboisreymondia Karsten (1848: 397) was published as a substitute genus for the illegitimate Duboisia, the author used the same type as that for Duboisia and proposed the replacement name Dubois-reymondia palpigera for Duboisia reymondii, but the new name was superfluous and illegitimate. Since the combination by Reichenbach (Pleurothallis reymondii) can be considered as a replacement for the Duboisia reymondii under article 58.1, the correct name for this species is Myoxanthus reymondii (Rchb. f.) Luer. Myoxanthus reymondii is similar to M. cimex but can be distinguished by the generally obtuse dorsal sepal that is not completely open vs. dorsal sepal acute, completely open and reflexed, covering the ovary and pedicel, apex of the petals round, thickened vs. ovate, thickened and lip with small acute lateral lobes vs. oblong, without lateral lobes.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828531FF26FA74FA86F974.taxon	materials_examined	TYPE: — BRAZIL. Espírito Santo: Santa Teresa, Valsugana Velha, Santa Lúcia Biological Station, 750 m, 16 Jun 2001 (fl), Fraga 780 (holotype: MBML!; isotype: RB).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828531FF26FA74FA86F974.taxon	distribution	Distribution: — Southeastern Brazil. Notes: — Like M. conceicionensis, M. lonchophyllus and M. punctatus, this species is endemic to southeastern Brazil and has a dark red to purple-spotted perianth, lip base with a small auricle on both sides and margins revolute to the apex and the characteristic fimbriate anther cap. However, M. ruschii is easily recognized among these by its elliptic to ovate petals vs. ovate at the base then narrow with revolute margins forming rounded linear petals.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828532FF26F8E8FECBFED4.taxon	materials_examined	TYPE: — ECUADOR. Napo: epiphytic in forest 15 Km west of Tena, 600 m, 26 Jul 1975, Luer, Luer & Wilhelm 621 (holotype: SEL!; isotype: K!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF828532FF26F8E8FECBFED4.taxon	distribution	Distribution: — Ecuador. Notes: — According to Luer (1992), this uncommon species endemic to central Ecuador is closely related to M. octomerioides. However, its yellowish flowers are morphologically similar to those of M. congestus and M. pulvinatus. This species is recognized by its abaxially slightly pubescent yellowish flowers and petals with the margins above the middle thicker, forming a sulcus at the abaxial surface, a feature shown in the illustration of the type and the photo here (Fig. 18 B).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FE88FF0BFCF9.taxon	materials_examined	Type: — COSTA RICA. Cartago: La Estrella, Lankester & Sancho 401 (holotype: AMES!; isotype: AMES!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FE88FF0BFCF9.taxon	distribution	Distribution: — Costa Rica. Notes: — This proliferous species was described from Costa Rica in 1923 by Ames and reported by Luer (1992) to occur also in Panama and Ecuador. However, as discussed by Rojas-Alvarado & Karremans (2020), the material from Panama and Ecuador belongs to different species. The Ecuadorian plants are likely to be M. pennellius (see M. penellius notes), whereas those cited for Panama are M. panamense. Myoxanthus scandens is most similar to M. pennellius, but the former is recognized by its sepals with an acute apex vs. obtuse to round, wider petals basally that conspicuously contract into a thickened narrow apex vs. narrowly ovate petals, slightly contracted above the middle, a lip with two longitudinal lamellae above the middle vs. lip with two longitudinal lamellae from the base to near the apex.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FC6CFD77FA38.taxon	materials_examined	TYPE: — PERU. Junín: Huanacayo, epiphytic in the valley of Pariahuanca between Panti and Rocchac, 2400 ‒ 2600 m, 31 Mar 1913, Weberbauer 6538 (holotype: B, destroyed, lectotype, designated here, the isotype MOL 8372).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FC6CFD77FA38.taxon	distribution	Distribution: — Ecuador and Peru. Notes: — This is the largest and most distinctive species of Myoxanthus. The flowers are dark red to dark purple with the column yellowish, long sepals (up to 3 cm) densely covered adaxially by circular to subcircular warts. The petals are obovate at the base, abruptly contracted above the middle, forming a narrow, oblong to linear apex. The lip is ovate to trilobate with lateral lobes erect bellow the middle and margins serrate to fimbriate and apex verrucose; it has a subclavate column and fimbriate anther cap. The most similar species is M. oliviae, which is distinguished by brownish to yellowish flowers and sagittate petal apex. Myoxanthus serripetalus is found in the high Andes of Ecuador and Peru, above 2000 m elevation. Because the holotype of Pleurothallis serripetalus was destroyed at B, an isotype preserved at MOL is designated here as lectotype.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FA2CFD7DF85C.taxon	materials_examined	TYPE: — VENEZUELA. Bolívar: Apácara-tepui, Río Tirica, 1700 – 1850 m, 23 Jun 1953, Steyermark 75957 (holotype: AMES; isotype: NY!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF818532FF26FA2CFD7DF85C.taxon	distribution	Distribution: — Guyana and Venezuela. Notes: — This species has been reported from only Guyana and Venezuela. It is caespitose with slender ramicauls and narrow leaves producing successive single flowers. The habit is similar to M. hirsuticaulis and M. merae, but the yellowish to brownish flowers with abaxially shortly pubescent sepals are most similar to M. merae, which is only found in Ecuador and Peru. It is distinguished from M. merae by the wider petals with a more pronounced narrow, thickened apical section, more pronounced and oblique lateral lobes of the lip and a pair of longitudinal calli emerging below the middle of the lip extending to the base.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FF60FA5DFDBC.taxon	materials_examined	Type: — COSTA RICA. Cartago: Jiménez, Pejibaye, La Marta, shore of Río Pejibaye, 9 º 47 ’ 47 ” N 83 º 42 ’ 55 ” W, 690 m, epiphytic in secondary vegetation along the river, premontane wet forest, 10 Jan 2004, Pupulin 5044 (holotype: CR!, photo, illustration of type, CR!; isotype: JBL spirit).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FF60FA5DFDBC.taxon	distribution	Distribution: — Costa Rica. Notes: — For years, this proliferous species remained unnoticed and misidentify as M. scandens, the only previously known proliferous species reported for Costa Rica. Myoxanthus sotoanus is recognized by linear leaves and flowers with brownish sepals, yellowish translucent petals and yellow lip. The most similar species is M. panamense, but M. sotoanus is distinguished from the former by the brownish sepals vs. greenish translucent and yellow lip vs. purple.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FDB0FAF2FBA0.taxon	description	(1962: 268). TYPE: — Colombia. Amazonas, Schultes 8584 (holotype: IAN!; isotype: AMES).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FDB0FAF2FBA0.taxon	distribution	Distribution: — Nicaragua, Costa Rica, Panama, Venezuela, Colombia, Ecuador, Peru and western Brazil. Notes: — This widely distributed species is easily recognized among Myoxanthus species by the short, repent habit and yellow flowers. The only other species of the genus with a repent habit is M. hystrix, but its flowers are easily distinguished. Myoxanthus trachychlamys has yellow flowers with acute, oblong sepals and petals and oblong lip with a small, acute lobe on the lateral margins, whereas M. hystrix has yellowish flowers with purple veins, triangular petals with the base contracted and a subclavate apex, a small, oblong, recurved lip and column with broad wings.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FB94FE9EF9A8.taxon	materials_examined	TYPE: — ECUADOR. Zamora-Chinchipe: epiphytic in cloud forest east of the pass between Loja and Zamora, 2500 m, 11 Feb 1978, Luer, Luer & Portilla 2533 (holotype: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF808533FF26FB94FE9EF9A8.taxon	distribution	Distribution: — Colombia and Ecuador. Notes: — Myoxanthus uxorius is caespitose with narrow leaves generally with revolute margins and yellowish glabrous flowers that are similar to M. ruschii from Brazil, but M. uxorius is distinguished by its unmottled sepals and petals vs. darkly mottled, column foot without calli vs. with a pair of thick calli near the apex, yellow lip suffused with brown, obovate arcuate, convex above the middle, the disc with a pair of smooth, rounded calli bellow the middle vs. reddish to brownish, obovate, with angled elevated margin near the middle and revolute slightly verrucose margins above the middle.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF80853CFF26F99CFAFCF80E.taxon	materials_examined	TYPE: — ECUADOR. Zamora-Chinchipe: Estación Científica San Francisco, between Loja and Zamora, 2010 m, 7 Feb 2005, Werner 1481 (holotype: MO, not located).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF80853CFF26F99CFAFCF80E.taxon	distribution	Distribution: — Ecuador. Notes: — According to the protologue, the type was deposited at MO, but the specimen was not located when it was requested. Luer compared it with M. affinis and suggested it could be distinguished from the latter by the fleshy flowers with wider sepals and petals and an oblong lip that is acutely arcuate near the middle. The photo (Fig. 18 K) here fits the description and illustration of M. werneri, the most diagnostic features, the wide broad sepals, arcuate lip and bidentate column apex. FIGURE 18. Myoxanthus species. A. M. ruschii. B. M. sarcodactylae. C. M. scandens. D – E. M. serripetalus. F. M. simplicaulis. G – H. M. sotoanus. I. M. trachychlamys. J. M. uxorius. K. M. aff. werneri. L. M. xiphion. Photographs by: E. Luiger (A). J. Ponert (B). D. Bogarín (C). A. Hirtz (D). G. Verhellen (E). L. & M. Karlbom (F). G. Rojas-Alvarado (G, H, I). E. Schulz (J, K). S. Vieira-Uribe (L).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF8E853DFF26FF60FC04FE60.taxon	materials_examined	TYPE: — Ecuador. Napo: epiphytic in wet forest south of Baeza, 1500 m, 11 Aug 1978, Luer, Luer, Andreetta & Hirtz 3267 (holotype,: SEL!).	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
0E3EF64DFF8E853DFF26FF60FC04FE60.taxon	distribution	Distribution: — Ecuador, Colombia, Bolivia and Peru. Notes: — This species is similar to M. parvilabius in having lateral sepals connate at the base forming a flat synsepal and falcate petals. However, M. xiphion is distinguished by the caespitose habit vs. proliferous, yellowish flowers vs. purplish and subquadrate base of the petals, trilobed just above the middle and abruptly contracted into a falcate middle lobe vs. obovate base contracted into a slender falcate apex.	en	Rojas-Alvarado, Gustavo, Blanco, Mario A., Karremans, Adam P. (2021): A taxonomic synopsis and morphological characterization of Myoxanthus (Orchidaceae: Pleurothallidinae). Phytotaxa 507 (3): 211-258, DOI: 10.11646/phytotaxa.507.3.1, URL: http://dx.doi.org/10.11646/phytotaxa.507.3.1
