ORCHIDACEAE
Epipogium J.G. Gmel. ex Borkh., Tent. Disp. Pl. German. 139 (1792).
By: Lokesh R. Shakya
Taxon Description
Plants terrestrial, holomycotrophic. Rhizome tuberous or coralloid. Stem erect, fleshy, slender, glabrous, with sheathing bracts, leafless. Inflorescence terminal, racemose, few- to many-flowered. Fertile bracts ovate or ovate-lanceolate. Flowers resupinate or non-resupinate, pedicellate, variously coloured, ovary dilated. Sepals and petals similar, free. Lip ovate-cordate or elliptic-cordate, concave, spurred, entire or 3-lobed, disk papillate, with longitudinal ridges or lamellae, spur saccate or elongate, straight or curved, obtuse. Column short, fleshy, lacking a column foot, pollinia 2, each deeply cleft, clavate, loosely granular-farinaceous, each with a slender caudicle attached to a viscidium, stigma distant from broad rostellum.
Taxon Statistics
Worldwide about 7 species, distributed in tropical Africa, temperate and tropical Asia, NE Australia, Europe, SW Pacific islands. Three species in Nepal
Key to Species
1a Rhizome coralloid. Flowers non-resupinate ……………………………….… 1. E. aphyllum
b Rhizome tuberous. Flowers resupinate …………………………………………………….. 2
2a Spur pendulous, curving forward away from ovary, 6–9 mm, longer than ovary ……………………………………………………………………………….… 2. E. japonicum
b Spur projecting backward, nearly parallel to ovary, ca. 3 mm, shorter than ovary ……………………………………………………………………………………….. 3. E. roseum
1. Epipogium aphyllum Sw., Summa Veg. Scand. 32 (1814).
Plants 10–20 cm. Rhizome coralloid, ca. 2.5 cm. Stem somewhat tapering upwards, sheathed, sheaths amplexicaule, ca. 8 mm, membranous. Rachis 2–3 cm, laxly 2- or 3-flowered. Fertile bracts ovate, 6–7 X 3–4 mm. Flowers non-resupinate, pinkish white or white marked with pale mauve, ca. 10 mm, across. Pedicel and ovary ca. 5 mm. Sepals and petals similar, oblong-lanceolate, ca. 10 X 2.5 mm, spreading, acute. Lip cordate-ovate, 8 X 6–10 mm, concave, 3-lobed; lateral lobes erect, triangular, mid-lobe cordate, margins slightly erose, disc with 4-6 longitudinal, papillose ridges, spurred; spur large and thick, ca. 4 mm, as long as ovary, slightly flattened, obtuse. Column ca. 6 mm.
Distribution: Nepal, W Himalaya, E Himalaya, temp.Eurasia.
Altitudinal range: 3,600 m.
Ecology: In shady wood.
Flowering: August–September.
2. Epipogium japonicum Makino, Bot. Mag. (Tokyo). 18: 131 (1904).
Plants 15 cm. Rrhizome tuberous, 1–3 cm. Stem sheathed; sheaths 2, amplexicaule, ca. 7 mm, membranous. Rachis 2–3 cm, laxly 3-flowered. Fertile bracts ovate-lanceolate, ca. 10 X 4 mm, acute. Flowers resupinate, brown with pink to maroon spots and striations on sepals, petals and lip, ca. 10 mm across. Pedicel and ovary ca. 12 mm. Sepals and petals similar, ovate-lanceolate, 8–11 X 3–5 mm, weakly or widely spreading, acute. Lip cordate-ovate, 8–12 X 9–10 mm, concave, entire, lateral margins incurved, spurred; disk densely papillose; spur pendulous and curving forward away from ovary, elongate cylindric, 6–9 mm, longer than ovary. Column ca. 8 mm.
Distribution: Nepal, E Himalaya, Japan, Taiwan.
Altitudinal range: 2,300 m.
Ecology: In moist broad-leaved forests.
Flowering: October.
As the only known specimen from Nepal (BB Raskoti 001267 KATH) is in a poor condition, the floral characters described above are based on the description in Flora of China.
3. Epipogium roseum (D.Don) Lindl., J. Proc. Linn. Soc., Bot. 1: 177 (1857).
Limodorum roseum D.Don, Prodr. Fl. Nepal.: 30 (1825).
Plants 20–40 cm. Rrhizome tuberous, oblong or fusiform, ca. 3.5 cm. Stem sheathed; sheaths 1–6, tubular, 6–16 mm, membranous. Rachis 2–8 cm, laxly many-flowered, apex curved. Fertile bracts ovate or ovate-lanceolate, 6–7 X 3–4 mm, as long as or longer than ovary. Flowers resupinate, white with yellow purple spots, 10–15 mm, across. Pedicel and ovary 5–7 mm. Sepals subsimilar, oblong-lanceolate, ca. 7 X 2.5 mm, weakly spreading, acute. Petals oblong-lanceolate, ca. 10 X 2.5 mm, weakly spreading, acute. Lip elliptic-ovate, 10 X 8–10 mm, margins erose-denticulate, disc with 2 papillose ridges, spurred; spur projecting backward, nearly parallel to ovary, cylindric, ca. 3 mm, shorter than ovary, obtuse. Column 2–4 mm.
Distribution: Nepal, W Himalaya, E Himalaya, tropical and subtropical Asia, Africa, SW Pacific.
Altitudinal range: 1,000 m.
Ecology: On floor of Schima–Castonopsis Forest.
Flowering: May.