ORCHIDACEAE
Chiloschista Lindl., in Edward’s Bot. Reg. 18: t. 1522 (1832).
By: Lokesh R. Shakya
Taxon Description
Plants epiphytic, monopodial, usually stemless and leafless or leaves present only in young plants. Roots numerous, dense, elongate, flat, green. Inflorescence racemose, pendulous. Flowers resupinate. Sepals subequal, lateral sepals adnate to column foot. Petals often adnate to column foot. Lip sessile, without spur, jointed or adnate to the long-produced foot of the column, base saccate or conical, lateral lobes large, erect, midlobe minute. Column short, subterete, foot long, operculum with 2 long, filiform setae, pollinia 4, in 2 closely appressed, unequal sessile pairs.
Taxon Statistics
Worldwide about 25 species, distributed in tropical and subtropical Asia to NW Pacific. Two species in Nepal.
Key to Species
1a Outer surface of sepals and petals hirsute. Flowers greenish yellow with brown spots …………………………………………………………………………………… 1. C. parishii
b Outer surface of sepals and petals glabrous. Flowers white …………………………………………………………………………………. 2. C. usneoides
1. Chiloschista parishii Seidenf., Opera Bot. 95: 176 (1988).
Stem inconspicuous. Inflorescence pendulous, racemose, 12–20 cm, laxly many-flowered. Peduncle 1–2.5 cm, green, pubescent, with sterile bracts. Rachis pubescent. Fertile bracts ovate-lanceolate, ca. 2 mm, equaling the ovary. Flowers with sepals and petals yellow or greenish yellow with brown spots, lip yellow with broad brown bands, 1–1.6 cm across, subsessile. Pedicel and ovary ca. 3 mm, pubescent. Dorsal sepal ovate, ca. 5 X 3.5 mm, outer surface hirsute, concave. Lateral sepals spreading, slightly longer, broadly ovate, ca. 5 X 3.5 mm, obtuse, hirsute outside. Petals spreading, broader than the sepals, subquadrate, ca. 5 X 4 mm, hirsute outside. Lip ca. 8 mm, 3-lobed, saccate at base, midlobe blunt, emarginate, lateral lobes larger, subquadrate, erect, incurved, disc with an erect, fleshy, pubescent callus. Column ca. 1.2 mm, foot ca. 3 mm.
Distribution: Nepal, E Himalaya and Assam-Burma.
Altitudinal range: 1300–2400 m.
Ecology: Epiphytic on Shorea robusta.
Flowering: March–April.
2. Chiloschista usneoides (D.Don) Lindl. in Edwards Bot. Reg. 18: sub t. 1522 (1832).
Epidendrum usneoides D.Don, Prodr. Fl. Nepal.: 37 (1825).
Stem inconspicuous. Inflorescence pendulous, racemose, 7–10 cm, laxly many-flowered. Peduncle 1–2.5 cm, brownish, pubescent, with sterile bracts. Rachis 5–8 cm, pubescent. Fertile bracts lanceolate, ca. 2 mm, equaling the ovary. Flowers with sepals white with red-purple flush outside, sepals and petals white within, lip white, ca. 1.2 cm across, subsessile. Pedicel and ovary ca. 4 mm, pubescent. Sepals similar, oblong, 6 X 4 mm, obtuse, spreading, glabrous outside. Petals ovate, ca. 6 X 4 mm, spreading, glabrous outside. Lip ca. 5 mm, 3-lobed, saccate at base, linear-oblong, lobes, erect, incurved, midlobe smaller, truncate, emarginate, disc densely pubescent, without callus. Column ca. 1.5 mm, foot ca. 3.5 mm.
Distribution: Nepal, W Himalaya, E Himalaya, Assam-Burma, SE Asia.
Altitudinal range: 1000–1500 m.
Ecology: Epiphytic on tree trunks in moist sheltered sites.
Flowering: March–April.