ORCHIDACEAE
Cleisostoma Blume, Bijdr. 362. (1825).
By: Lokesh R. Shakya
Taxon Description
Plants epiphytic, monopodial. Stems erect or pendulous, short or elongated, branched or unbranched, noded. Leaves few to many, distichous, sheathing at the base, glabrous, dorsiventrally flattened or terete, leathery, apex 2-lobed or acute. Inflorescence lateral or leaf opposed, a few to many flowered, racemose. Flowers small, resupinate. Sepals subequal, spreading, free. Petals free, spreading, usually somewhat shorter and narrower than the dorsal sepal. Lip rigidly adnate to the column, fleshy, 3-lobed, spurred. Column foot usually absent; rostellum small, pollinia 4, equal or unequal, stipe present, viscidium present.
Taxon Statistics
Worldwide about 100 species, distributed in tropical and subtropical Asia to W Pacific. Four species in Nepal.
Key to Species
1a Leaves terete ……………………………………………………………………………… 2
b Leaves dorsiventrally flattened ………………………………………………………….. 3
2a Plants pendulous. Stem 25-60 cm. Petals linear, ca. 0.6–1 mm wide ……… 2. C. filiforme
b Plants ascending. Stem 5-20 cm. Petals oblong, ca. 1.5 mm wide ………… 4. C. simondii
3a Inflorescence much exceeding leaves. Lateral lobes of lip triangular, entire …………………………………………………………………………….. 3. C. racemiferum
b Inflorescence as long as or slightly exceeding leaves. Lateral lobes of lip, rounded, erose ……………………………………………………………………………… 1. C. aspersum
1. Cleisostoma aspersum (Rchb. f.) Garay, Bot. Mus. Leafl. 23(4): 169 (1972).
Sarcanthus aspersus Rchb.f., Hamburger Garten- Blumenzeitung 21: 297 (1865).
Plants ca. 15 cm tall. Stem stout, 4–6 cm, leafy, covered by leaf sheaths at base; sheaths overlapping. Leaves 4 or 5, coriaceous, dorsiventrally flattened, oblong, 7.5–13 X 2–2.5 cm, deeply and obliquely bifid, the lobules often erose, with distinct 4 or 5 veins. Inflorescence ascending, arising from base of leaf sheaths, as long as or slightly exceeding leaves, branched and many-flowered; peduncle slender having a few distant sheathing bracts. Fertile bract ovate-triangular, ca.1 mm. Flowers ca. 8–10 mm across; sepals and petals yellow with lip white with pink patch, column white. Sepals subequal, spreading. Dorsal sepal ovate-elliptic, 5 X 2 mm, obtuse. Lateral sepals broadly elliptic 5 X 2 mm, obtuse. Petals oblong, ca. 4 X 1 mm, obtuse. Lip ca. 5 mm, 3-lobed, fleshy, adnate to the column, base with spur; lateral lobes erect, broad, rounded, erose; the apical lobe fleshy, broad, ovate, concave, acute. Column ca. 4 mm.
Distribution: Nepal, NE India and Myanmar.
Altitudinal range: 900 m.
Ecology: Epiphyte on Persea odoratissima.
Flowering: July-August.
2. Cleisostoma filiforme (Lindl.) Garay, Bot. Mus. Leafl. 23(4): 171 (1972).
Sarcanthus filiformis Lindl., Bot. Reg. 28 : misc.61, no .69 (1842).
Plants pendulous. Stem slender, 25–60 cm, branched or unbranched, laxly many leaved. Leaves distant, elongate, terete, 5–10 X 0.5 cm, cylindric, acuminate. Inflorescence 15–30 cm, racemose, curved, extra axillary, shorter or longer than the leaves, laxly many flowered, peduncle with sheathing bracts at the base. Fertile bract broadly ovate, ca. 3 mm, shorter than pedicel and ovary. Flowers 9 mm across between two lateral sepals, sepals and petals yellowish green, lip white; tip of the apical lobe pink. Sepals subequal. Dorsal sepal ovate, 3.2 X 2.0 mm, concave, obtuse. Lateral sepals ovate, 3.8 X 2.5 mm, obtuse. Petals linear, ca. 3.3 X 0.6 mm, obtuse. Lip 2.7 mm and 4 mm high, broadly conical, fleshy, spurred, 3-lobed; lateral lobes triangular, acute, incurved; midlobe sagittate-triangular with curved apex; spur oblong, obtuse, dorsiventrally compressed, ca. 2.5 mm. Column ca. 3 mm.
Distribution: Nepal, NE India, Myanmar, China, Thailand and Vietnam.
Altitudinal range: 500-900 m.
Ecology: Epiphytic on Ficus.
Flowering: July — August.
3. Cleisostoma racemiferum (Lindl.) Garay, Bot. Mus. Leafl. 23(4): 173 (1972).
Saccolabium racemiferum Lindl., Gen. Sp. Orchid. Pl.: 224 (1833).
Plant 28–38 cm tall. Stem stout, large, ca. 10 cm, leafy, covered by leaf sheaths at base; sheaths overlapping. Leaves many, coriaceous, dorsiventrally-flattened, oblong, 18–23 X 3.5–4 cm, obliquely bifid, the lobules entire, with distinct single mid-vein. Inflorescence ascending, axillary, much exceeding leaves, much branched and many-flowered panicle; peduncle slender having a few distant sheathing bracts. Fertile bract triangular, ca.1 mm. Flowers ca. 8–10 mm across; sepals and petals brownish with white lip, column white. Sepals subequal, spreading. Dorsal sepal 3 X 2 mm, broadly-elliptic, acute. Lateral sepals broadly elliptic, 3 X 2 mm, acute. Petals oblong, ca. 3 X 1 mm, obtuse. Lip ca. 5 mm, 3-lobed, fleshy, adnate to the column, base with spur; lateral lobes erect triangular, entire; the apical lobe fleshy, ovate, concave, acute, with an incurved apical beak. Column ca. 2.5 mm.
Distribution: Nepal, India, Bhutan, Myanmar, China, Thailand and Vietnam.
Altitudinal range: 1100 -1600 m.
Ecology: Epiphytic on main girth of Kaula tree.
Flowering: August-September.
4. Cleisostoma simondii (Gagnep.) Seidenf., Dansk Bot. Ark. 29(3): 66. (1975).
Vanda simondii Gagnep., Bull. Mus. Natl. Hist. Nat., sér. 2, 22: 628 (1951).
Plants often ascending. Stem slender, 5–20 cm, usually unbranched, laxly many leaved. Leaves distant, terete, 4–10 X 0.4 cm, cylindric, acuminate. Inflorescence 5–15 cm, racemose, leaf opposed, shorter or longer than the leaves, laxly many flowered, peduncle with sheathing bracts at the base. Fertile bract broadly ovate, ca. 2 mm, shorter than pedicel and ovary. Flowers 7–9 mm across between two lateral sepals, sepals and petals yellowish green with purplish red veins, lip white; tip of the apical lobe pink. Sepals subequal. Dorsal sepal oblong, 4.5 X 3.5 mm, obtuse. Lateral sepals oblong, slightly oblique, 4.5 X 3 mm, obtuse. Petals oblong, ca. 3.5 X 1.5 mm, obtuse. Lip 3 mm, 2 mm high, broadly conical, fleshy, spurred, 3-lobed; lateral lobes triangular, acute, incurved; midlobe triangular with curved apex; spur oblong, obtuse, dorsiventrally compressed, ca. 3.5 mm. Column ca. 4 mm.
Distribution: Nepal, NE India, Laos, China, Thailand and Vietnam.
Altitudinal range: 400 – 900 m.
Ecology: Epiphytic on Acacia catechu and Schima wallichii.
Flowering: October.