ORCHIDACEAE
Rhomboda Lindl., J. Proc. Linn. Soc., Bot. 1: 181 (1857).
By: Bhakta B. Raskoti
Taxon Description
Terrestrial herbs. Rhizome creeping, noded; nodes with fibrous, villous roots. Stem erect, glabrous, with tubular sheaths at base. Leaves usually crowded at stem apex, green-red, median vein often white, lanceolate, ovate, or elliptic, oblique, apex acute, base petiole-like amplexicaul sheath. Inflorescence erect, terminal, racemose, pubescent; peduncle with a few scattered sheathing bracts; rachis laxly to subdensely flowered; floral bracts sparsely pubescent. Flowers half opening,resupinate or not resupinate. Ovary and pedicel not twisted, glabrous to sparsely pubescent. Sepals free, similar, ovate-elliptic. Petals hooded with dorsal sepal, often dilated. Lip lobed; hypochile saccate, with a basal rhomboid callus and longitudinal carina along median vein forming abicarinatecallus toward apex; outside of hypochile with flanges; mesochile less commonly present, very short; epichilevariously shaped, entire or lobed, apiculate. Column winged; anther ovoid, 2-locular; pollinia 2, sectile, clavate,viscidium ovate; rostellum deltoid, bifid; stigma lobes 2, convex. Capsule narrowly ovoid, erect.
Taxon Statistics
Worldwide 25 species, distributed in Assam-Burma, Australasia, E Asia, E Himalaya, Tibetan Plateau, SE Asia.One species in Nepal.
1. Rhomboda abbreviata (Lindl.) Ormerod, Orchadian. 11: 329 (1995).
Hetaeria abbreviata Lindl., Gen. Sp. Orchid. Pl. 481 (1840); Anoectochilus abbreviatus (Lindl.) Seidenf; Odontochilus abbreviatus (Lindl.) Tang & F. T. Wang; Zeuxine abbreviata (Lindl.) Hook. f.
Plants 25–33 cm tall. Stem 4–9 cm, with 3–7-leaved. Leaves abaxially pale green, sometimes tinged with red, adaxially dark green, ovate-lanceolate, 4–8 × 1.5–2.5 cm, apex acute; petiole-like base and tubular sheath 1.5–3 cm. Peduncle 10–18 cm, with 2 or 3 sterile bracts; sterile bracts ovate-lanceolate, ca. 1–1.5 × 3-5 cm, apex acute; rachis 3–8 cm, laxly 8–13-flowered. Floral bracts ovate, 5–10 × 2–3 mm, shorter than to equal to ovary, margin ciliate, apex acuminate. Flowers half opening,resupinate, ca.3–5 mm across, greenish white, petals and lip white. Ovary and pedicel 6–10 mm, glabrous. Dorsal sepal broadly ovate, 2–3.5 × 1.5–2 mm, apex acute. Lateral sepals obliquely ovate, ca. 2.5–4 × 2–2.5 mm, apex acute. Petals obliquely ovate-lanceolate, 2–3.5 × 1–1.5 mm, apex abruptly narrowed into a short apiculus. Lip cymbiform, broadly ovate, 2.5–3.5 mm, obscurely 3-lobed; hypochile concave-saccate, ca. 2–2.5 × 2–2.5 mm, base with 2 oblong-ellipsoid calli; carina in median vein forming a laminate callus near apex; mesochile ca. 0.5 mm, margin involute; epichile obtriangular, ca. 1–1.5 × 1 mm, margin involute, apex truncate, apiculate. Column ca. 2 mm.
Distribution: Nepal, Assam-Burma, E Asia, E Himalaya, and SE Asia.
Altitudinal range: 600–1600 m.
Ecology: Shady damp areas.
Flowering: August–September. Fruiting: September–November.
Rhomboda abbreviata is collected from Nepal (Wallich N. 7385 K-W). Above description is based on specimen from E Himalaya and SE Asia (Pantling R. 346 P; van Beusekom C.F. and Smitinand T. 2227 L, Meijer M. 5927 L).