ORCHIDACEAE
Papilionanthe Schltr., Orchis 9: 78 (1915).
By: Bhakta B. Raskoti
Taxon Description
Epiphytic, monopodial herbs. Roots fibrous. Stems erect, climbing or pendulous, terete, usually branched, noded. Leaves terete, fleshy, base sheathed. Inflorescence axillary, laxly flowered. Flowers opening widely. Sepals subsimilar, free, spreading. Petals subsimilar to sepals, free, usually larger than sepals. Lip immovable, spurred, 3-lobed, lateral lobes erect, sometime deeply lobed, mid-lobe often bifid at apex. Column straight, with a distinct foot; pollinia 2-locular, attached with viscidium by subquadrate stipe, rostellum slender. Fruit a capsule.
Taxon Statistics
Worldwide 10 species, distributed in E Asia, S Asia and SE Asia. Two species in Nepal.
Key to Species
1a Plants erect. Inflorescence longer than leaves. Lateral lobes of lip not bifid (entire)………………………………………………………………..……..1. P. teres
b Plants pendulous. Inflorescence shorter than leaves. Lateral lobes of lip deeply bifid…………………………………….……..…………………..….….2. P. uniflora
1. Papilionanthe teres (Roxb.) Schltr., Orchis 9: 78 (1915).
Dendrobium teres Roxb., Fl. Ind. ed. 1832. 3: 485 (1832); Vanda teres (Roxb.) Lindl.
Plants up to 1 m tall. Stem erect, stout, branched. Leaves terete, 8–11 × 0.3–0.4 cm, apex obtuse. Inflorescence racemose, longer than leaves, 10–15 cm, laxly 2–5-flowered, peduncle with 3 or 4 sheaths. Peduncle bracts broadly ovate, 4 × 4 mm, apex obtuse. Floral bracts broadly ovate, 4–5 × 3–4 mm, apex obtuse. Flowers with sepals and petals white, tinged with pink or purple, lip deep purple-red, spur yellowish brown, 4–5 cm across. Pedicel and ovary 2–2.5 cm. Dorsal sepal broadly elliptic, 2–3 × 2–2.5 cm, apex obtuse-rounded. Lateral sepals obliquely ovate to oblong, 2.5–3.5 × 1.4–2 cm, apex obtuse. Petals suborbicular, 2.5–3 × 2.5–2.8 cm, apex obtuse, margin weakly undulate. Lip spurred, adnate to the column foot, 3-lobed, lateral lobes subobovate, 1.5–2 × 1–1.5 cm, entire, rounded, mid-lobe obovate-triangular, 2 × 2 cm, deeply bilobed, spur conical, 1.7–2 cm. Column 5 mm, foot 4 mm. Capsule cylindrical, ca. 5–6 × 1 cm.
Distribution: Nepal, E Himalaya, Assam-Burma, E Asia, S Asia and SE Asia.
Altitudinal range: 200–900 m.
Ecology: Epiphytic on tree trunks or large branches in broadleaved forests.
Flowering: May–June. Fruiting: July–November.
2. Papilionanthe uniflora (Lindl.) Garay, Bot. Mus. Leafl. 23: 372 (1974).
Mesoclastes uniflora Lindl., Gen. Sp. Orchid. Pl.: 45 (1830); Luisia uniflora (Lindl.) Blume
Plants up to 1 m tall. Stem pendulous, stout, branched. Leaves terete, 13–17 × 0.2–0.3 cm, apex acute. Inflorescence racemose, shorter than leaves, 2–3 cm, laxly 1- or 2-flowered, peduncle with 2 or 3 sheaths. Peduncle bracts ovate, 2 × 2 mm, apex obtuse. Floral bracts ovate, 2 × 1.5 mm, apex acute. Flowers white, tinged with pink, spur yellowish, 2–3 cm long. Pedicel and ovary 1.5–5 cm. Dorsal sepal oblong, 8–10 × 4 mm, apex obtuse-apiculate. Lateral sepals oblong, falcate, 10–12 × 3 mm, apex obtuse-apiculate. Petals oblong, 9 × 5 mm, apex obtuse, margin undulate. Lip spurred, adnate to the column foot, 3-lobed, lateral lobes unequally bifid, long lobule linear, 4–5 mm, short lobule filiform, 3 mm, mid-lobe oblong, 4 × 1 mm, apex bifid, spur infundibuliform, 15–20 mm. Column 4–5 mm, foot 5 mm. Capsule cylindrical, 3–5 × 0.4–0.5 cm.
Distribution: Nepal, E Himalaya and Assam-Burma.
Altitudinal range: 1500–2100 m.
Ecology: Epiphytic on tree trunks in evergreen forests.
Flowering: August–September. Fruiting: October–December.
Dubious species:
Papilionanthe vandarum (Rchb. f.) Garay , Bot. Mus. Leafl. 23: 372 (1974).
Aerides vandarum Rchb.f., Gard. Chron. 1867: 997 (1867).
Note: Press et al. (2000), Rajbhandari and Dahal (2004) and Rokaya et al. (2013) mentioned the presence of Papilionanthe vandarum in Nepal no specimens have been seen to confirm this.