Lockhartia endresiana M.A.Blanco, 2014

Blanco, Mario A., 2014, Four new species of Lockhartia (Orchidaceae, Oncidiinae), Phytotaxa 162 (3), pp. 134-146 : 137-139

Lockhartia endresiana M.A.Blanco , sp. nov. ( Figs. 2 , 5A )

Similar to Lockhartia grandibractea Kränzlin (1923: 15) , but differs from that species in the structure of the callus, which consists of six to eight longitudinal, denticulate, gill-like keels (vs. an irregular mass of tubercles in L. grandibractea ), and in the narrower basal lobes of the labellum.

Type:— COSTA RICA. Alajuela: San Ramón, camino a Colonia Palmareña , 600 m, 10°51’06”N 84°31’06”W, collected without flowers on 23 January 2001 by M. Blanco, R. Moran, E. Watkins & E. Vargas, flowered in cultivation at Lankester Botanical Garden on 15 July 2002, Blanco 1803 (holotype: USJ!) .

Stems erect, more or less rigid, 15−35 cm long when reproductive, with 28−48 leaves; shoots (stem and leaves) 8−20 mm wide. Leaves marcescent, unifacial, laterally flattened, triangular in side view, acute, with straight to incurving margins, exposed part of largest leaves 5−19 × 3−6 mm. Inflorescences both terminal and axillary from the distal part of the stem, with 1−3 flowers produced more or less simultaneously; exserted portion 1−3 cm long; inflorescence bracts amplexicaul, infundibuliform, subrotund, cordate, obtuse to round apically, 8 × 8−9 mm; pedicel and ovary 14 mm long. Flowers resupinate, widely open, 14−18 mm tall; yellow with dark chocolatebrown markings on the lateral lobes, disk, and central keels of callus of the labellum, and a dark brown line at the base of the column; occasionally spotted on the upper part of the column and at the base of the petals. Sepals ovate to elliptic, slightly concave, obtuse, 6−7 × 4−5 mm. Petals oblong-elliptic, slightly incurved, with revolute margins, rounded to truncate apically, 7−7.5 × 4−4.5 mm when flattened. Labellum 3-lobate; the lateral lobes oblong, incurved, 6 × 1.5 mm, apically obtuse to rounded; midlobe divided in 4 lobules (the two basal ones triangular and projected backward, the two distal ones rounded when flattened), apically emarginate, 10.5−11 mm long, 10.5−11.5 mm wide (across the widest part of midlobe when flattened); callus subpandurate, the basal part forming a subquadrate concave cushion with a basal tuft of short, glandular hairs, 2 × 2 mm, the distal part formed by 6−8 high (to 1.5 mm tall), subparallel, denticulate keels, 4 × 3.5 mm when labellum is flattened. Column hastate, truncate, held perpendicular to the labellum, 3−3.5 mm long, 4.5−5 mm wide at base, 2.3 mm wide distally; anther cap hemispherical, 1−1.3 mm in diameter; pollinarium not seen. Fruits not seen.

Phenology:— Field collections indicate that flowering occurs from March to September, during Costa Rica’s rainy season.

Distribution:— Presently known only from Costa Rica, from 600 to 1,450 m on the Caribbean slope of the Guanacaste and Tilarán cordilleras and on the Pacific slope of the Talamanca cordillera. Several collections from places close to the Panamanian border suggest that L. endresiana also occurs in adjacent Chiriquí province of Panama, but I have not seen any flowering collections from that country; specimens without flowers would be impossible to distinguish from L. amoena Endrés & Rchb. f. (in Reichenbach 1872: 666) and L. grandibractea .

Additional specimens examined:— COSTA RICA. Without additional locality data, cultivated: 19 October 1994, LeDoux & Stern 355 ( MO) . Alajuela: Guatuso, Cote, Lago Cote , 640 m, 4 June 2004, Gómez-Laurito 14314 ( USJ) , same location, flowered in cultivation in Cartago, 3 June 2013, Blanco 4152 (USJ) ; San Ramón, camino a Colonia Palmareña , 600 m, 10°51’06”N 84°31’06”W, collected without flowers on 23 January 2001 by M. Blanco, R. Moran, E. Watkins & E. Vargas, flowered in cultivation at Lankester Botanical Garden on 23 June 2004, Blanco 1803 ( FLAS; not an isotype because the specimen was prepared on a different date) . Cartago: Turrialba, Guayabo , 16 September 1991, Mora s.n. ( USJ-spirit no. 57678) ; Turrialba, Tayutic, Vereh, Grano de Oro, 2 km al E, camino a Llanos del Quetzal , 1200 m, 28 July 1995, Herrera & Cascante 8163 ( CR, F, K) . Guanacaste: Guatuso, Cordillera de Tilarán, Lago Coter , 700 m, 18 May 1997, Rivera 3080 ( CR) ; Liberia, Parque Nacional Guanacaste, Estación Cacao , 1100 m, 1 June 1990, Carballo 40 ( CR) . Puntarenas: Buenos Aires, Boruca , 700−1000 m, July 1976, Ocampo 1423 ( CR) ; Coto Brus, San Vito, Estación Biológica Las Cruces, Sendero Ridge , 28 August 2008, Oviedo-Brenes 214 ( HLDG) , 1219 m, 16 August 1967, Raven 21820 ( F) , 1 mile due S of San Vito de Java , 1067 m, 18 August 1967, Raven 21906 ( CR, DUKE, F, PMA, SEL, U) ; Río Sirena [Río Sereno?], Sabalito , 1991, Soto s.n. ( USJ-spirit no. 57681) ; Zona Protectora Las Tablas, Finca Las Alturas, road from Las Alturas to Fila Tigre , 1450 m, 3 July 2004, Pupulin et al. 4493 ( JBL-spirit ) ; Zona Protectora Las Tablas, Finca Las Alturas, road from Las Alturas to Fila Tigre , 1450 m, 22 March 2003, Pupulin et al. 4518 ( JBL-spirit ) .

Conservation status:— Although not too common, Lockhartia endresiana seems to be well distributed in Costa Rica and has been found in or near several protected areas. This species is not threatened.

Etymology:— The epithet honors Augustus R. Endrés (1838–1874; Ossenbach et al. 2010), who first illustrated this species. Endrés also collected the type specimens (or the living plants that served as material for the types) of five other species names in Lockhartia , i.e., L. amoena Endrés & Rchb. f., L. cladoniophora Reichenbach (1888: 150) , L. grandibractea Kraenzl. , L. hercodonta Kränzlin (1923: 8) , and L. odontochila Kränzlin (1923: 17) .

Comments:— Lockhartia endresiana is the only species in the genus that has a callus composed of thin, raised (up to 1.5 mm), gill-like keels. It is most similar to L. grandibractea , with which it shares the general shape of the labellum and column. Both species have a hastate column (as seen from below, due to the column wings being twice as wide at the proximal half than at the distal half), and it is impossible to distinguish them in the absence of flowers. However, L. endresiana differs by the structure of its callus (composed of a compact mass of low tubercles in L. grandibractea ). A few collections from the area around the Costa Rican-Panamanian border are intermediate between both species, which suggests that hybridization occurs between them. Both species flower mostly during the rainy season, which would permit this. Despite the existence of these intermediates, the callus morphology is very different and clearly distinguishable in most collections, and, in my opinion, this justifies their treatment as different species.

Lockhartia endresiana and L. grandibractea have been commonly confused with L. amoena in herbaria, and even L. grandibractea has been considered a synonym of L. amoena in recent treatments of Costa Rican Orchidaceae (e.g., Pupulin 2002, Dressler 2003). Although superficially similar, L. amoena differs from both L. endresiana and L. grandibractea in its less deeply lobed labellum midlobe, and in its much larger, subquadrate column wings that are wider distally and with a crenate margin.

Augustus Endrés prepared a detailed drawing of Lockhartia endresiana (Endrés 302, W-Reich.-Orch. no. 33697), which includes a stem with an inflorescence, front and side view of the flower, a detail of the callus base with the elaiophore, six details of the column, and the pollinarium with detached pollinia. At the bottom and on the right side of the sheet there are drawings of a column with wide, flabellate wings, likely representing L. amoena . There is no indication of the original locality for any of these elements in the drawing, and their corresponding vouchers have not been found and may have not been preserved.

Figures

FIGURE 2. Lockhartia endresiana M.A.Blanco. A. Plant habit. B. Flower, front view. C. Flower, lateral view. D. Same as previous, with sepals and lateral petals removed. E. Dissected perianth parts (flattened, except lateral petal on right), with column in center (ventral view). F. Floral bract, flattened. Scale bar: 5.5 cm (for A), 1.0 cm (for B–F). Drawing by the author; A, based on Carballo et al. 40 (CR); B–F based on Blanco 1803 (FLAS).

FIGURE 5. Flowers of three Lockhartia species described in this paper; live plants used to prepare vouchers (cited in parentheses). A. Lockhartia endresiana (Blanco 4152, USJ). B–C. Lockhartia rugosifolia (Whitten 2432, FLAS, QCA); flowers in frontal and lateral views, respectively. D–F. Lockhartia tenuiflora (Blanco 3012, FLAS, SEL-spirit); flowers in frontal and lateral views, and inflorescence, respectively. Photos B and C by Mark W. Whitten; all other photos by the author.