Vanilla calyculata Schltr.

Pansarin, Emerson R., 2025, Systematics of the Vanilla chamissonis clade (Orchidaceae): a study based on integrative taxonomy, Plant Ecology and Evolution 158 (2), pp. 260-278 : 260-278

Vanilla calyculata Schltr. (Schlechter 1920: 42)

Figs 2 , 4 , 6 , 5 , 7 , Table 1

Vanilla esquipulensis Archila & Chiron ( Archila and Chiron 2012: 6) – Type: GUATEMALA • El Barrial, Esquipulas, Chiquimula; 900 m; Apr. 2012; F. Archila 1300; holotype: BIGU!.

Type

COLOMBIA – Cauca • 1000 m; M. Madero s. n.; holotype: B †. – Valle del Cauca • Tuluá, Corregimiento Mateguadua, Jardín Botánico Juan Maria Céspedes, laderas en vía de repoblación natural , 1100 m a. s. l.; 28 Sep. 1984; W. Devia 815; neotype (designated by Soto Arenas and Dressler 2010): TULV! [ TULV 003790 ]; isoneotype NY! [ NY 04170480 ] .

Description

Nomadic vines, long scandent. Roots axillary, one per node; terrestrial roots up to 10 mm diam., fleshy, whitish, with white-hyaline absorbing hairs; aerial roots 2.2–2.8 mm diam., creamy to brownish. Stem climbing, cylindrical, fleshy, sinuous, glabrous, green, strongly furrowed under arid conditions; internodes of ascending stems 7–16 × 0.6–1.2 cm. Leaves 8–21 × 2–4 cm, alternate, distichous, linear to lanceolate, symmetric, fleshy, glabrous, green, pseudopetiolate, margin often revolute, base rounded, apex acute; pseudopetiole 6–10 mm long, concave. Inflorescence axillary, racemose, with up to 20 flowers opening in succession; 1–3 flowers opening each morning; rachis 6–11 × 1.1–1.8 cm, terete, green; bracts 6.5–10 × 4.5–8 mm, progressively smaller to the apex, widely deltoid, coriaceous, concave, green, apex acute, involute. Flowers resupinate, pedicellate, abscission layer between perianth and ovary present; pedicel with ovary 42–56 × 4.5–5.5 mm, cylindrical, sulcate, whitish at the base, green to the apex, with a calyculus (7.5–8.5 × 3.5–4.5 mm) at the apex. Sepals 7.5–8 × 1–1.4 cm, free, narrowly oblanceolate to oblong-elliptic, slightly concave, revolute, white at the base, green to the apex, margin entire, base attenuate, apex subacute to obtuse, somewhat thickened; dorsal sepal symmetric; lateral sepals asymmetric. Petals 7.5–8 × 0.9–1.3 cm, free, obliquely linear-oblanceolate, asymmetric, lower margin more arcuate, membranous, white at the base, green to the apex, base attenuate, apex acute to rounded, adaxial surface with central and longitudinally disposed keel. Labellum 3 - lobed, 8.8–9.5 × 3.7–4.5 cm, tubular, deepening near the middle, yellowish to the base, dark yellow at the distal half and with white lobes, unguiculate, with a central crest from the unguiculus to the apex, and a penicillate callus just below the anther; unguiculus fused along the margins of the basal half (ca 41–46 mm) of column length forming a nectar chamber; nectar chamber 3.2–3.6 mm long, tubular; central crest whitish from the nectar chamber to the penicillate callus, yellow to the apex; distal portion of central crest swollen, low cushion, rugose-papillose at the apex, with a group of transversal and yellow-orange hairs near the penicillate callus, longitudinal lines not much evident; penicillate callus ca 4.5 × 3.8 mm, made up by 8–10 flabellate, shortly lacerate-laciniate and retrorse scales; lateral lobes rounded, bilobed, overlapping the column apex, margins entire; midlobe deeply emarginate to bilobed, margins crenulate-undulate. Column 55–60 × 4–4.5 mm, subterete, subclavate, sigmoid, ventral surface flat with white to yellowish hyaline trichomes over the distal half, dilated to the apex, with two lateral wings; lateral wings with two triangular-flabellate protrusions, narrow, undulate. Stigma bilobed; rostellum 4.2–4.6 × 2.8–3.2 mm; trapezoid, flabellate. Anther 5.2–6 × 4–4.3 mm, rectangular, apex truncate to slightly emarginate; pollen mass 1.9–2.1 × 3.7–4.2 mm, triangular, bipartite, yellow. Fruits 15–21 × 2–3 cm, oblong, transversally terete to subtrigonous, fleshy, yellowish and dehiscent when mature, fragrant; pericarp hard; fruit cavity hollow. Seeds ca 0.5 mm, ovoid, black.

Distribution and ecology

Vanilla calyculata is distributed throughout dry forests of Brazil, El Salvador, Guatemala, Honduras, and Colombia (Fig. 4 ). In Colombia, this species is widely distributed in the inter-Andean valleys in the western and central Andean cordilleras, at elevations between 500 and 1750 m a. s. l. When found at lower elevations, the vegetation is sub-xerophytic. In Brazil, this species occurs predominantly in the Caatinga.

Phenology

Vanilla calyculata blooms from September to November in Brazil. The fruits ripen from June to July. Flowering in Colombia corresponds to two annual periods with higher precipitation: April – May and September – October. Flowers were recorded in April in El Salvador, Guatemala, and Honduras.

Preliminary IUCN conservation assessment

Endangered: EN B 2 ab (i, ii, iii). Vanilla calyculata is a species distributed throughout dry forests of Brazil, Colombia, El Salvador, Guatemala, and Honduras. The species is rarely collected in Brazil and the populations are composed of few sparse specimens. The extent of occurrence (EOO) is estimated to be 4,145,682 km 2, which falls within the limits for Least Concern (LC) under criterion B 1, according to the IUCN Red List categories and criteria. The area of occupancy (AOO) is estimated to be 92 km 2, which falls within the limits for Endangered (EN) under criterion B 2. In Colombia, the tropical dry forest is distributed across the Caribbean and Eastern (Llanos) plains, and in the inter-Andean valleys in the Cauca and Magdalena watersheds. This ecosystem has been highly transformed for agriculture, cattle grazing, and urbanization, with only 8 % of the original landcover remaining. The tropical dry forest ecosystem in Colombia is categorized as CR – critically endangered, with a representativity in the Colombia National Protected Area System ( SINAP) of only 5 %. In Brazil, the Caatinga vegetation has been reduced to the expansion of human activities in northeastern Brazil. Considering habitat fragmentation, besides the climatic changes that have reduced the raining period in the habitat of V. calyculata specially in Brazil, I project a continuing decline in (i) extent of occurrence, (ii) area of occupancy, and (iii) extent and / or quality of habitat for this species. Based on these threats and the fact that the species is distributed in less than five locations, V. calyculata is assessed as Endangered: EN B 2 ab (i, ii, iii).

Additional material examined

BRAZIL – Bahia • Conceição do Coité, Salgadália. Próximo às casas populares ; 28 Nov. 2012; D. N. Carvalho 173; HUEFS • s. loc.; 28 Oct. 2008; C. E. Ramos et al. 528; US . – Minas Gerais • Unaí, Ilha a montante do túnel de desvio, cerca de 500 m da ponte de madeira, Margem esquerda do Rio Preto ; 12 Sep. 2002; A. Amaral-Santos 1508; CEN • Unaí, Fazenda Saco Grande, margem do córrego, próximo à casa do Sr. Teodorim ; 16 Oct. 2019; A. Amaral-Santos 3758; CEN .

COLOMBIA – Cauca • El Socavón, Mercaderes ; 1200 m; 3 Feb. 1990; M. Rocio Galindez 103; AFP • Piedrasentada, vereda Piedra Rica ; 980 m; 4 May 2002; R. J. C. Muñoz 010; AFP • Vereda Potrerillo, Patía ; 624 m; 25 Jan. 2015; G. Reina Rodriguez, I. Nichols, F. Lopez & J. Reyna 2122; FMB . – Cundinamarca • Finca “ El Descanso ”, vereda Chinauta, Fusagasugá ; 1200 m; 3 Apr. 1988; F. Sarmiento 2140; BOG . – Huila • Between La Jagua & Altamira ; 880 m; 23 Jul. 1961; L. A. Garay, C. E. McClennen & A. Kapuler 277; AMES . – Nariño • Vía Mojarras-Leyva, vereda Puerto Nuevo, Finca La Sortija, Leyva , Vegetación de Bosque seco; 576 m; 24 Jan. 2015; G. Reina-Rodriguez, I. Nichols, F. Lopez & J. Reyna 2101; FMB . – Santander • Reserva natural de la sociedad civil La Montaña Mágica – El Pole, Zapatoca ; 1750 m; 17 May 2017; D. Díaz Rueda, R. Diaz Rueda & L. Rivera 1369; MEDEL . – Tolima • La Plata ; 800–1500 m; 3 Dec. 1882; F. C. Lehmann 2263; BM . – Valle del Cauca • Hacienda El Carmen, carretera La Uribe-Sevilla ; 1140 m; 19 Jul. 1994; P. Silverstone-Sopkin & N. Paz 6933; CUVC • Finca la Josefina , La Herradura, Bolivar; 1076 m; 5 Aug. 2010; G. Reina Rodriguez & M. Moreno 1344; FMB • Corregimiento Loboguerrero, Dagua ; 730 m; 31 Jul. – 4 Aug. 1998; W. G. Vargas 4643; COL, HUA • Atuncela, Corregimiento Loboguerrero, Dagua ; 950 m; Jul. 1998; W. G. Vargas 6087; ICESI • Reserva Forestal Bosque Yotoco ; 27 May 2007; F. Rojas 62; UDBC • Cultivated, Cali ; E. Dryander 2379; BM • Roldanillo, Valle ; 1000 m; F. C. Lehmann 8378; K .

EL SALVADOR – Depto. Morazán • Mpio. Arambala; 688 m; 7 Mar. 2018; Y. Ruiz s. n.; LAGU [ LAGUJBL 07763 ] • Mpio. Perquín, Crio. La Tejera ; 1038 m; 19 Jun. 2018; Y. Ruiz 720; LAGU • La Palma, Finca El Refugio, Río Nanuapa ; 1000 m; 3 Apr. 1969; O. Pank & F. Hamer 203; AMES .

GUATEMALA – El Barrial • Esquipulas , Chiquimula; 600 m; Mar. 1999; F. Archila s. n.; illustrated in Archila and Chiron (2012); BIGU • Río Jocotan , Chiquimula; 500 m; Apr. 2000; F. Archila s. n.; BIGU .

HONDURAS – Comayagua • Siguatepeque ; 1050 m; 23 Jul. 1936; T. G. Yuncker, R. F. Dawson & H. R. Youse 6045; K, NY, AMES • Quebrada Santa Clara, ca 2 km al norte del Zamorano, Mpio de San Antonio de Oriente ; 800 m; 19 Jun. 1996; J. L. Linares 3386; MEXU • El Paraiso, Quebrada El Cajocote, 8.7 km al N de Morocelí, por el camino a Mata de Plátano ; 680 m; 29 Apr. 2004; J. L. Linares 7313; MEXU • Las Mesas region near Yuscarán ; Aug. 1960; H. W. Pfeifer 1454; US .

Notes

Vanilla calyculata has been considered synonymous with V. columbiana , a species described based on a specimen collected in the Magdalena River valley, Colombia. However, the holotype of V. columbiana is clearly a V. phaeantha with immature flowers. For this reason, the name V. calyculata has been re-established and V. columbiana has been synonymized under V. phaeantha ( Flanagan et al. 2025) . Vanilla calyculata is one of four species found in tropical dry forest ecosystems in Colombia. In the Cauca valley, it occurs in sympatry with V. odorata , V. phaeantha , and V. pompona . Herbarium specimens of V. calyculata have been historically referred to as V. phaeantha . However, V. calyculata can be distinguished from V. phaeantha by its long leaves larger than the internodes, its pendant flowers, by its pedicels, petals and sepals with white bases, and by its ovary ending in a calyculus.

Morphological affinities

Vanilla calyculata occurs in dry forests. The species is recognized from the remaining species of the V. chamissonis clade by the following characters: long and linear to lanceolate leaf blades (Fig. 5 ), revolute sepals 7.5–8 cm long, labellum 8.8–9.5 cm long with a nectar chamber 3.2–3.6 cm long, column 55–60 mm long, and dehiscent fruit yellowish when mature with a hard pericarp (Figs 6 – 7 ). Several vegetative and reproductive characteristics support V. calyculata as a member of the V. chamissonis clade, such as the presence of an ovary ending in a calyculus, a labellum with emarginate midlobe, and a yellow-orange elevated central crest. The phylogenetic analysis supports V. calyculata as a member of the V. chamissonis clade (see further).

Figures

Figure 2. Vanilla calyculata Schltr. A. Part of a flowering plant showing the stem, leaves, and inflorescence. B. Inflorescence in lateral view showing a mature bud. C. Detail of an inflorescence showing an open flower in diagonal view. D. Flower in upper view. E. Dissected perianth. F. Detail of the apex of the labellum showing the yellowish longitudinal crest. The detail (dashed area) shows the penicillate callus. G. Pedicel / ovary and column in lateral view. H. Apex of the column: in diagonal view with an articulated anther (above), in lateral view with an articulated anther (mid), and in ventral view with a disarticulated anther (below). I. Apex of the column in ventral view showing the bilobed rostellum. J. Anther in ventral view. K. Pollen mass in dorsal view. L. Mature fruit. M. Transversal section of a mature fruit. Note the hollow fruit cavity. Based on VAN 206 (Vanilla germplasm bank, LBMBP Orchid House).

Figure 4. Occurrence map of Vanilla argentina, V. chamissonis, and V. calyculata.

Figure 5. Comparative morphology of leaves of related Vanilla species. A. V. argentina. B. V. calyculata. C. V. chamissonis. Scale bars = 2 cm. A from E. R. Pansarin 1570 (LBMBP), B from VAN 206 (Vanilla germplasm bank, LBMBP Orchid House), C from E. R. Pansarin 1579 (LBMBP).

Figure 6. Comparative morphology of perianth parts of related Vanilla species. A. V. argentina. B. V. chamissonis. C. V. calyculata. Lowercase letters on the right side of the floral parts are: (a) distended labellum, (b) labellum apex, (c) detail of the labellar crest, (d) petal. Scale bars = 2 cm. A from E. R. Pansarin 1570 (LBMBP), B from E. R. Pansarin 1579 (LBMBP), C from VAN 206 (Vanilla germplasm bank, LBMBP Orchid House).

Figure 7. Comparative morphology of mature fruits of related Vanilla species. A. V. argentina. B. V. chamissonis. C. V. calyculata. Details in figures are transversal (A, B) or longitudinal (C) sections of mature fruits. Scale bar = 2 cm. A from E. R. Pansarin 1570 (LBMBP), B from E. R. Pansarin 1579 (LBMBP), C from VAN 206 (Vanilla germplasm bank, LBMBP Orchid House).