Epidendrum vallis-silentii M.Díaz & Karremans, 2016

Díaz-Morales, Melissa & Karremans, Adam P., 2016, Epidendra Nova Talamancana, Phytotaxa 272 (4), pp. 248-256 : 253-255

Epidendrum vallis-silentii M.Díaz & Karremans , sp. nov.

Type:— COSTA RICA. Limón – Puntarenas: Talamanca–Buenos Aires, Bratsi– Potrero Grande, Parque Internacional La Amistad , Sector Altamira , sendero al Valle del Silencio , Cerro Hoffman , sobre la divisoria de aguas, bosque pluvial montano, 2,553 m, 9°05’38.2” N 82°58’37.73” W, 17 September 2014, A. P. Karremans 6320, M. Díaz, M. Fernández, C. Godínez, J. Godínez, L. Oses, J. Ramírez & D. Villalobos (holotype, JBL-spirit!; fig. 4 ) .

Diagnosis:— Epidendrum vallis-silentii belongs to the Epidendrum difforme Jacquin (1760: 29) complex. It is related to Epidendrum pachyceras Hágsater & Sánchez (1993: 170) , from which it is distinguished by the wider, white lip; the shorter, obtuse calli on the lip and the longer, arcuate, white column, and the densely fimbriate clinandrium-hood.

Epiphytic, sympodial, caespitose herb, 25–35 cm tall including the inflorescence. Roots basal, fleshy, 2–4 mm in diameter. Stems 10.5–26.5 × 0.8–1.2 cm tall, flexuose, laterally compressed, ancipitose. Leaves 2–9, distributed all along the stem; leaf sheath laterally compressed, ancipitose, smooth, 1.2–2.2 cm long; blade 4.0–7.5 × 1.8–3.5 cm, articulate, ovate to elliptic, bilobed, coriaceous, margin entire. Spathaceous bracts lacking. Inflorescence apical, from mature growth, racemose, flowering only once, erect. Floral bracts shorter than the ovary, acute, conduplicate, 3.0– 5.5 mm long, translucent. Ovary 3.0– 3.5 cm long, slightly inflated behind the perianth. Flowers 1–2, successive, resupinate, yellow-green, the lip and the column white. Sepals 28.5 × 8.7 mm, free, spreading, elliptic, acute, 7-veined, glabrous, margin revolute. Petals spreading, linear to oblanceolate, acute, 3-veined, margin revolute, 25.0 × 3.0 mm. Lip 20.0–22.5 × 18.5–20.0 mm, fused to the column, reniform, sides revolute, retuse, margins entire, bicallose, the calli thick, divergent, sub-globose. Column arcuate near the apex, thick, 21.0–22.0 mm long including the fimbriate clinandrium-hood, 3.0– 3.5 mm long; rostellum apical, slit. Anther and pollinia not seen. Capsule not seen. Note: Description based only on Karremans 6320.

Other material studied:— COSTA RICA. Puntarenas: Foothills of the Cordillera de Talamanca, trail between Tres

Colinas and Cerro Bekom, 2,500 m, 9°07–10’ N 83°04’ W, 28 March 1984, Davidse & Herrera Ch. 26195 (CR-INB!).

Distribution:—Known only from Costa Rica.

Etymology:—The name alludes to the locus typicus of the plant, Valle del Silencio, or “the valley of silence”.

Habitat in Costa Rica:—Known from the Cordillera de Talamanca, at about 2500 m elevation, in the Pacific slope and close to the continental divide.

Phenology: —Flowering in March, and in August under cultivation.

Figures

FIGURE 4. Epidendrum vallis-silentii M.Díaz & Karremans. Lankester Composite Digital Plate (LCDP) prepared from the plant that served as the holotype. A. habit. B. flower. C. dissected perianth. D. inflorescence. E. column (ventral and lateral views). F. lateral view of the column and the lip.