ORCHIDACEAE
Platanthera Richard, De Orchid. Eur.: 26 (1817).
By: Lokesh R. Shakya
Taxon Description
Terrestrial, rarely epiphytic herbs. Roots usually tuberous, cylindrical or narrowly fusiform, rarely ovoid, covered with minute hairs. Stem erect, rarely slightly curved, glabrous, basal sheath tubular. Leaves usually 1 or 2, rarely 3–5, basal or sub-basal, rarely arising from middle of stem, alternate, distant, rarely sub-opposite, oblong to oblong-elliptic or linear-elliptic, base sheathing. Inflorescence a terminal, few- to many-flowered raceme, sterile bracts 1 to 4, rarely absent, linear, lanceolate or linear-lanceolate, fertile bracts usually lanceolate, usually diminishing upwards. Flowers usually uniformly green or white, sometimes greenish yellow, small to medium-sized, resupinate or not. Sepals subsimilar. Dorsal sepal and petals forming a hood over column, rarely petals spreading and not forming hood, lateral sepals spreading or reflexed. Petals free, entire, oblong, lanceolate or ovate. Lip simple, spurred, entire, linear to linear-lanceolate, rarely oblong; spur usually pendulous, straight or incurved, shorter or longer than pedicel and ovary. Column short, stout, pollinia 2, sectile, clavate, caudicles conspicuous, attached to the naked viscidium, stigmas 2, rostellum triangular, with 2 divergent arms, stigma concave, lying below rostellum.
Taxon Statistics
Worldwide about 2000 species, distributed in Europe, N. America, north temperate Asia, the Malay Arcchipelago and New Guinea. 13 species in Nepal.
Key to Species
1a Leaves arising from middle of the stem …………………………………………………………… 2
b Leaves basal, sub-basal or lowermost leaf basal or sub-basal ……………………………………… 5
2 a Leaf 1. Inflorescence decurved. Spur urceolate ……………………………………. 13. P. urceolata
b Leaves 2–5. Inflorescence straight. Spur slender………………………………………………… 3
3 a Sterile bracts absent ……………………………………………………………… 9. P. sikkimensis
b Sterile bracts present ……………………………………………………………………………… 4
4a Leaves 4–5. Flowers white, 16 mm across ………………………………………….. 5. P. japonica
b Leaves 3. Flowers green, 6–7 mm across ………………………………………… 4. P. dologensis
5a Leaf 1 ………………………………………………………………………………………………. 6
b Leaves 2 or 3 ………………………………………………………………………………………. 9
6a Flowers non-resupinate …………………………………………………………… 12. P. superantha
b Flowers resupinate ………………………………………………………………………………….. 7
7a Lip 2 mm, spur ca. 1.2 mm, clavate ……………………………………… ….. 7. P. nematocaulon
b Lip more than 3 mm long, spur 5–14 mm, slender …………………………………………….… 8
8a Inflorescence 5–10 cm. Dorsal sepal oblong to oblong lanceolate. Lip 3–3.5 mm, spur 5–10 mm, slightly dilated at apex ……………….…………………… 8. P. pachycaulon
b Inflorescence more than 10 cm long. Dorsal sepal ovate. Lip more than 3.5 mm long, spur 12–14 mm, slightly dilated at middle …………………………..11. P. stenoglossa
9a Leaves alternate, subopposite ……………………………………………………. 2. P. carnoslabris
b Leaves alternate, distant ………….……………………………………………………………….10
10a Petals ovate-triangular ……………………………………………………………… 1. P. bakeriana
b Petals oblong, linear or lanceolate………………………………………………………………..11
11a Spur 5–6 mm, shorter than pedicel and ovary ………………………………. 3. P. dambungensis
b Spur 10–17 mm, longer than pedicel and ovary ………………………………………………..12
12a Spur 10–13 mm, apex acuminate ………………………………………………. 6. P. leptocaulon
b Spur 14–17 mm, apex dilated …………………………………………………… 10. P. stenantha
1. Platanthera bakeriana (King & Pantl.) Kraenzl., Orchid. Gen. Sp. 1: 632 (1899).
Habenaria bakeriana King & Pantl., J. Asiat. Soc. Bengal, Pt.2, Nat. Hist. 65: 132 (1896).
Plants terrestrial, 30–60 cm tall. Stem erect, stout, basal sheaths tubular. Leaves 2 rarely 3, lowermost leaf sub-basal, broadly elliptic, 8–10 X 1.5–5 cm, alternate, base clasping, acute. Inflorescence 20–30 cm, subdensely many flowered, raceme 5–20 cm, slender. Sterile bracts 2 rarely 1 or 3, linear-lanceolate, acuminate. Fertile bracts 10–18 X 2–3 mm, linear-lanceolate, acuminate, basal exceeding flowers, upper as long as pedicel and ovary. Flowers green or yellowish green, ca. 8 mm across, resupinate. Pedicel and ovary 10–12 mm. Dorsal sepal oblong-ovate, 3.5 X 1.5 mm, obtuse, 1-veined. Lateral sepals oblong-lanceolate, 4 X 1.8 mm, reflexed, acute, 1-veined. Petals erect, ovate-triangular, 3.4 X 1.7 mm, acute, 1-veined . Lip linear, 3.2 X 0.7 mm, slightly pendulous, obtuse; spur 7–17 mm, pendulous, cylindric, incurved, much longer than pedicel and ovary, apex acuminate. Column ca. 1.5 mm.
Distribution: Nepal, E. Himalaya, Assam-Burma.
Altitudinal range: 3000-4500 m.
Ecology: On mossy rocks.
Flowering: June–July.
2. Platanthera carnosilabris (Tang & F.T. Wang) X.H. Jin, Schuit. & W.T. Jin, Molec. Phylogen. Evol. 77: 51 (2014).
Herminium carnosilabris Tang & F. T. Wang in Bull. Fan Mem. Inst. Biol. Bot. 10: 32 (1940).
Plants terrestrial, 7.5–14 cm tall. Stem erect, slender, glabrous, basal sheath tubular. Leaves 2, sub-basal, subopposite, oblong, 2–3.5 X 0.5–1 cm, obtuse. Inflorescence 5–12 cm, subdensely 9 to 12-flowered; raceme 1–3.5 cm, slender. Sterile bracts 3 rarely 4, linear-lanceolate, acute. Fertile bracts ovate, 2 X 1 mm, acuminate, shorter than the ovary. Flowers uniformly green, ca. 4.5 mm across, resupinate. Pedicel and ovary ca. 3 mm. Dorsal sepal ovate, 2 X 1.2 mm, acute, 1-veined. Lateral sepals oblong-elliptic, 2 X 0.8 mm, acute, 1-veined. Petals spreading, lanceolate, 1.5 X 0.8 mm, subacute, fleshy, obtuse. Lip ovate-lanceolate, 2 X 1 mm, fleshy, obtuse, deflexed; spur ca. 1 mm, pendulous, conic, slightly incurved, shorter than ovary, stout, apex obtuse. Column ca. 0.8 mm.
Distribution: Nepal, E Himalaya and Assam-Burma.
Altitudinal range: 3400 m.
Ecology: Rhododendron forest.
Flowering: August – September.
3. Platanthera dambungensis K.Prasad, Rheedea 33(2):31-52 (2023).
Plants terrestrial, 34 cm tall. Stem erect, slender, glabrous, basal sheath tubular. Leaves 2, 7–10.5 X 1–3.5 cm, alternate, elliptic to oblong, acute, sheathing at base. Inflorescence 22 cm, laxly ca. 24 flowered; raceme 7 cm, slender. Sterile bracts 3, linear-oblong, acute. Fertile bract oblong-lanceolate, 10 –15 X 2–3 mm, acuminate, longer than ovary. Flowers green, ca. 7 mm across, resupinate. Pedicel and ovary 7–9 mm, apex curved. margin minutely ciliate. Dorsal sepal ovate, 3 X 1.5 mm, acute, 3-veined. Lateral sepals oblong, 4 X 1.5 mm, obtuse, 3-veined. Petals erect, oblong, 2.5 X 1 mm, margin irregularly crenulate, obtuse, 1-veined. Lip linear, oblong, 2.5 X 1 mm, base with short claws; spur 5–6 mm, pendulous, slightly incurved , shorter than the pedicel and ovary, apex acuminate. Column ca. 1.5 mm.
Distribution: Nepal, E Himalaya.
Altitudinal range: 2800 m.
Ecology: In temperate forest in humus & litter covered muddy places.
Flowering: July.
This is a new record for Nepal. This species was previously recorded from Lachen Valley, Sikkim as an endemic species.
4. Platanthera dulongensis X.H. Jin & Efimov, Nordic J. Bot. 30: 294 (2012).
Plants epiphytic, 26 cm tall. Stem erect, slender, glabrous, stout, basal sheaths overlapping, tubular. Leaves usually 3, arising from the middle of stem, alternate, narrowly-lanceolate, 8–17 X 1–2 cm, acute to acuminate, sessile; sheathing at base. Inflorescence 13 cm, densely many-flowered, raceme ca. 8 cm, slender. Sterile bracts 3, oblong, acuminate. Fertile bracts lanceolate, 6 X 1.5 mm, longer than the ovary. Flowers green, 6–7 mm across, resupinate. Pedicel and ovary 3.5 mm, glabrous. Dorsal sepal narrowly-ovate, 2–3.5 X 1.5 mm, obtuse, 1-veined. Lateral sepals lanceolate, 2.5–3 X 0.6–0.9 mm, slightly oblique, obtuse, 1-veined. Petals broadly falcate-lanceolate, 2–2.5 X 1 mm, obtuse, 1-veined. Lip ligulate-lanceolate, 2.2–2.8 X 1.7–1.9 mm, obtuse, spur 6–10 mm, pendulous, slender, longer than pedicel and ovary, apex acute. Column ca. 1.3 mm.
Distribution: Nepal, E.Himalaya.
Altitudinal range: 2800 m.
Ecology: Epiphytic.
Flowering: October.
5. Platanthera japonica (Thunb.) Lindl., Gen. Sp. Orchid. Pl.: 290 (1835).
Orchis japonica Thunb. in Murraya (ed.), Syst. Veg., ed. 14.: 811 (1784).
Plants terrestrial, 40–58 cm tall. Stem erect, slender, glabrous, basal sheath tubular. Leaves 4–5, alternate, oblong-elliptic to oblong-lanceolate, 10–12 X 2.5–4 cm, sheathed at base, sheaths tubular; obtuse or acute. Inflorescence 12–19 cm; laxly many-flowered, raceme 12 cm, slender, glabrous. Sterile bracts 3 or 4, foliaceous, lanceolate, acuminate. Fertile bracts lanceolate, 3.2 X 0.7 cm, acuminate, longer than the ovary. Flowers uniformly white, ca. 16 mm across, resupinate. Pedicel and ovary straight to slightly aurcate, cylindric, ca. 15 mm. Dorsal sepal ovate, 8 X 3 mm, subacute, 3-veined. Lateral sepals ovate, 8 X 3 mm, subacute, 3-veined. Petals erect, linear, 8 X 1 mm, obtuse, 1-veined. Lip linear, 10–15 mm, simple, thick, with a pair of blunt teeth near base, obtuse; spur 30-40 mm, pendulous, slender, weakly incurved, longer than pedicel and ovary, apex acute. Column ca. 2–3 mm.
Distribution: Nepal, W. Himalaya, E. Himalaya and Assam.
Altitudinal range: 2400-2800 m.
Ecology: Oak forest.
Flowering: June – August.
6. Platanthera leptocaulon (Hook. f.) Soo, Ann. Hist.-Nat. Mus. Natl. Hung. 26: 360 (1929).
Habenaria leptocaulon Hook. f., Fl. Brit. India 6(1): 154 (1890).
Plants terrestrial, 25–32 cm tall. Stem erect, slender, glabrous, basal sheath overlapping, tubular. Leaves 2, alternate, linear-oblong, 10–11 X 1.5–2.5 cm, acute, sessile, long sheathed. Inflorescence 22 cm; laxly 9-flowered, raceme ca. 7 cm, slender. Sterile bracts 2, rarely 3, linear to linear-oblong, acute. Fertile bracts lanceolate,12 X 2.5 mm, acuminate, longer than the ovary. Flowers uniformly green, ca. 8 mm across, resupinate. Pedicel and ovary 8–9 mm, glabrous. Dorsal sepal oblong-elliptic, 4–5 X 1 mm, acute 3-veined. Lateral sepals oblong-elliptic, 4–5 X 1 mm, acute, reflexed. Petals erect, fleshy, lanceolate, 4.5 X 1 mm, subacute. Lip fleshy, oblong, 3–4 mm, obtuse, entire, deflexed; spur 10–13 mm, pendulous, longer than ovary, slender, stout, slightly incurved. Column ca. 2 mm.
Distribution: Nepal, E Himalaya and Assam-Burma. .
Altitudinal range: 2500-3500 m.
Ecology: Rhododendron forest.
Flowering: June-July.
7. Platanthera nematocaulon (Hook.f) Kraenzl., Orchid. Gen. Sp. 1: 942 (1901).
Habenaria nematocaulon Hook.f., Fl. Brit. India 6: 154 (1890).
Plants terrestrial, 18–23 cm tall. Stem erect, slender, glabrous, basal sheath tubular. Leaf 1, oblong, 2.5 X 1 cm, sheathing at base, obtuse. Inflorescence 8–10 cm, laxly 5 to 6 flowered, raceme 2–3 cm, slender. Sterile bracts 1 rarely 2, oblong-lanceolate, acuminate. Fertile bracts lanceolate, 6 X 1.5–2 cm, acuminate, as long as the pedicel and ovary. Flowers green or pale green, ca. 2 mm across, resupinate. Pedicel and ovary 2.5–3 mm. Dorsal sepal lanceolate, 2 X 1 mm, acuminate, 1-veined. Lateral sepals lanceolate, 2 X 1 mm, acute, slightly oblique, 1-veined. Petals erect, ovate, 2 X 1 mm, slightly oblique, acute, 1-veined. Lip broadly lanceolate, 2 X 1 mm, spur 1.2 mm, pendulous, clavate, incurved, shorter than pedicel and ovary, apex obtuse. Column ca. 1.5 mm.
Distribution: Nepal, E Himalaya, China.
Altitudinal range: 3400 m.
Ecology: On humus rich slopes.
Flowering: July.
This is a new record for Nepal.
8. Platanthera pachycaulon (Hook. f.) Soo, Ann. Hist.-Nat. Mus. Natl. Hung. 26: 364 (1929).
Habenaria oligantha Hook. f., Fl. Brit. India 6: 154 (1890).
Plants terrestrial, 17–30 cm tall. Stem slender, glabrous, basal sheaths tubular. Leaves 1 occasionally 2, alternate (2-leaves), elliptic to oblong-elliptic, 3–8 X 1.5–3 cm, sessile; base shortly sheathing, subacute. Inflorescence 5–10 cm, 5–8-flowered, raceme ca. 8 cm, slender. Sterile bracts few, oblong, acute. Fertile bracts linear-lanceolate, 10 X 2 mm, as long as or slightly longer than the ovary, acuminate. Flowers uniformly green or yellowish green, ca. 8 mm across, resupinate. Pedicel and ovary curved, beaked, glabrous, 7–10 mm. Dorsal sepal oblong to oblong-lanceolate, 3 X 2 mm, 3-veined, margins minutely ciliate, subacute . Lateral sepals oblong-lanceolate, 3 X 1 mm, 3-veined, margins minutely ciliate, subacute. Petals erect, ovate, 3 X 1.5 mm, slightly incurved. Lip simple, linear-lanceolate, 3–3.5 X 1 mm, fleshy, obtuse; spur 5–10 mm, pendulous, slender, stout, slightly wider at apex, slightly incurved, as long as or shorter than pedicel, apex obtuse. Column ca. 1 mm.
Distribution: Nepal, W Himalaya, E Himalaya and Assam-Burma.
Altitudinal range: 2400-2800 m.
Ecology: In Oak forest.
Flowering: June – August.
9. Platanthera sikkimensis (Hook. f.) Kraenzl., Orchid. Gen. Sp. 1: 621 (1898).
Habenaria sikkimensis Hook. f., Fl. Brit. India 6(1): 155 (1890).
Plants terrestrial, 14–18 cm tall. Stem slender, glabrous, basal sheaths overlapping, tubular. Leaves 2 or 3, alternate, oblong-elliptic, 7–8.5 X 1–2.8 cm, acute, sessile; sheathing at base; sheaths tubular. Inflorescence 8–10 cm, laxly 4–10-flowered; raceme ca. 5–8 cm, slender, sparsely pubescent. Sterile bracts absent. Fertile bracts linear-lanceolate, 2–2.7 X 0.4–0.5 cm, acuminate, foliaceous, longer than the ovary. Flowers uniformly green, 10–18 mm across, resupinate. Pedicel and ovary strongly curved, glabrous, 6–8 mm. Dorsal sepal concave, broadly ovate, 6–7 X 4.5 mm, obtuse, 3-veined. Lateral sepals oblong-lanceolate, 6–7 X 2 mm, acuminate, spreading, 3-veined. Petals erect, triangular-lanceolate, falcate, 8 X 1.5–2 mm, acuminate. Lip linear to linear-lanceolate, broad at base, 7–9 mm, caudate-acuminate; spur 10–12 mm, slender, stout, apex incurved and dilated, longer than ovary, apex obtuse. Column ca. 3 mm.
Distribution: Nepal, E Himalaya and Assam-Burma.
Altitudinal range: 2500-4000 m.
Ecology: On open places.
Flowering: July – August.
10. Platanthera stenantha ((Hook. f.) Soo, Ann. Hist.-Nat. Mus. Natl. Hung. 26: 363 (1929).
Habenaria stenantha Hook. f., Fl. Brit. India 6: 153 (1890).
Plants terrestrial, 40–60 cm tall. Stem erect, slender, glabrous, stout, sheathed at base, basal sheaths overlapping, tubular. Leaves usually 3 rarely 2, distant along stem, alternate, oblong-lanceolate, 12–15 X 1–4 cm, acute to subacute, sessile; sheathing at base, sheaths tubular. Inflorescence 21–44 cm, laxly many-flowered, raceme ca. 10–16 cm, slender. Sterile bracts 3-4, oblong, acuminate. Fertile bracts linear-lanceolate, 13–15 X 3–5 mm, acute to acuminate, basal longer than the ovary. Flowers green to yellowish green, 12–16 mm across, resupinate. Pedicel and ovary 10–12 mm, glabrous. Dorsal sepal oblong to oblong-ovate, 6–7 X 3–3.5 mm, obtuse, erect, 3-veined. Lateral sepals linear to linear-lanceolate, 7 X 2.5 mm, obtuse, deflexed, 3-veined. Petals erect, linear, 8 X 1.5–2 mm, obtuse, slighty broad at base. Lip linear, 8–9 mm, obtuse, margins entire; spur 14–17 mm, pendulous, yellowish, slender, stout, slightly incurved, longer than pedicel and ovary, apex acute. Column ca. 1.6 mm.
Distribution: Nepal, E Himalaya and Assam-Burma.
Altitudinal range: 2400-3500 m.
Ecology: In Rhododendron forest.
Flowering: July – August.
11. Platanthera stenoglossa Hayata, Icon. Pl. Formosan. 4: 123 (1914).
Plants terrestrial, 44 cm tall. Stem erect, glabrous, basal sheath tubular. Leaf 1, oblong-elliptic, 11 X 4 cm, acute, sheathing at base. Inflorescence 25 cm, laxly 11 flowered, raceme 13 cm, slender. Sterile bracts 2, oblong-lanceolate, acuminate. Fertile bracts oblong, 1–2 X 0.2–0.3 cm, acuminate, slightly longer than the ovary. Flowers pale green, ca. 10 mm across, resupinate. Pedicel and ovary 8–12 mm, arcuate. Dorsal sepal ovate, 4 X 2–3 mm, concave, acute, 1-veined. Lateral sepals linear, 6 X 1 mm, reflexed, obtuse, 1-veined. Petals erect, ovate-triangular, 5 X 3 mm, slightly oblique, erect, acute, 2-veined. Lip linear-lanceolate, 7 X 2 mm, acute, spur 12–14 mm, horizontal to pendulous, cylindric, slightly dilated in middle, incurved, as long as or slightly longer than ovary, apex acute. Column ca. 2.5 mm.
Distribution: Nepal, E Asia.
Altitudinal range: 3200 m.
Ecology: In open places in temperate forest.
Flowering: September.
12. Platanthera superantha (J.J. Wood) X.H. Jin, Schuit, Raskoti & Lu Q.Huang, Cladistics 32(2): 210 (2015).
Peristylus superanthus J.J. Wood, Kew Bull. 41: 811 (1986).
Plants terrestrial, 6–18 cm tall. Stem erect, slender, glabrous, basal sheath tubular. Leaf 1, oblong, 2.5 X 1 cm, obtuse, sheathing at base. Inflorescence 8–10 cm, laxly 5 to 6 flowered; raceme 2–3 cm, slender. Sterile bracts 2 to 4, ovate-elliptic to linear, acute. Fertile bracts lanceolate, 6 X 1.5–2 cm, acuminate, as long as the ovary. Flowers white or pale pink, ca. 2 mm across, non-resupinate. Pedicel and ovary 2.5–3 mm. Dorsal sepal lanceolate, 2 X 1 mm, acuminate, 1-veined. Lateral sepals lanceolate, 2 X 1 mm, slightly oblique, acute, 1-veined. Petals erect, ovate, 2 X 1 mm, acuminate, 1-veined. Lip oblong-ligulate, 4 X 0.5–0.8 mm, obtuse, 3-veined, spur 2 mm, clavate, slightly incurved, shorter than pedicel and ovary, apex obtuse. Column ca. 1.5 mm.
Distribution: Nepal, E.Himalaya, Assam-Burma.
Altitudinal range: 3500 m.
Ecology: Under deep shade in Rhododendron forest.
Flowering: August.
13. Platanthera urceolata (C.B. Clarke) R.M.Bateman, Ann. Bot. (Oxford) 104: 439 (2009).
Habenaria urceolata C.B.Clarke, J. Linn. Soc., Bot. 35: 73 (1889).
Diphylax urceolata (C.B. Clarke) Hook.f. in Hooker’s Icon. Pl. 19: pl. 1865 (1889).
Plants terrestrial, 6–10 cm tall. Stem erect-curved, slender, glabrous, with a single sheath at the base. Leaf 1, narrowly elliptic-oblong, 3.5 X 1 cm, arising below middle of stem, tapering towards base, base sheathing. Inflorescence 4 cm, laxly 12 flowered, decurved; raceme ca. 3 cm, slender. Sterile bracts 1-3, lanceolate, acute. Fertile bracts oblong-lanceolate, 6 X 2 mm, acute, as long as the ovary. Flowers white with green lip, not widely open, ca. 10 mm across, resupinate. Pedicel and ovary 5–6 mm. Dorsal sepal oblong-lanceolate, 5 X 1 mm, acute, 1-veined. Lateral sepals oblong-lanceolate, 4 X 1 mm, acute, 1-veined. Petals erect, oblong, 4 X 1 mm, obtuse, 1-veined. Lip linear, 4 X 0.5 mm, decurved beyond the middle, spur 2 mm, pendulous, urceolate, constricted at neck, shorter than pedicel and ovary, apex obtuse. Column ca. 3 mm.
Distribution: Nepal, E.Himalaya, Assam-Burma.
Altitudinal range: 3000-3500 m.
Ecology: On mossy stone in forest.
Flowering: August.