ORCHIDACEAE
Rhynchostylis Blume, Bijdr. Fl. Ned. Ind.: 285 (1825).
By: Bhakta B. Raskoti
Taxon Description
Epiphytic, monopodial herbs. Rhizome stout, with thick fibrous roots. Stem terete, stout, leafy. Leaves many, oblong, thickly fleshy, channeled, jointed and sheathing at base, unequally bilobed. Inflorescences lateral, pendulous, racemose, densely many-flowered, peduncle and rachis stout. Flowers resupinate, fully opened. Sepals similar, spreading, lateral sepals slightly wider. Petals similar to sepals, smaller in size. Lip adnate to column foot, immovable, entire, spurred at base; spur laterally compressed and backward-pointing. Column short, with distinct foot; rostellum long pointed; pollinia 2, globose, stipe long; viscidium ovate. Fruit a capsule.
Taxon Statistics
Worldwide 4 species, distributed in South Asia, South East Asia and East Asia. One species in Nepal.
1. Rhynchostylis retusa (L.) Blume, Bijdr. Fl. Ned. Ind.: 286 (1825).
Epidendrum retusum L., Sp. Pl.: 953 (1753); Aerides retusa (L.) Sw.; Gastrochilus retusus (L.) Kuntze; Saccolabium retusum (L.) Voigt
Plants 20–42 cm tall. Rhizome stout with fibrous roots. Stem pendent, 2–6 cm, covered by leaf sheaths. Leaves oblong, 11–26 × 2–2.5 cm, apex unequally bilobed. Inflorescences 1–3, pendulous, 19–30 cm, rachis 15–23 cm, densely flowered. Peduncle bracts ovate, 5–10 × 2–3 mm, apex obtuse. Floral bracts reflexed, broadly ovate, 3–5 × 2 mm, apex acute. Flowers sepals, petals white with pink spots, lip purplish, 10–15 mm across; pedicel and ovary 5–10 mm. Dorsal sepal elliptic, 5–9 × 3–5 mm, apex obtuse. Lateral sepals obliquely oblong, 6–9 × 4–5 mm, base adnate to column foot, apex obtuse. Petals oblong, 6–8 × 2–3 mm, apex obtuse. Lip oblong-spathulate, 7–10 × 5–6 mm, apex slightly retuse, base spurred; spur saccate, 4–7 mm. Column ca. 3–4 mm, foot ca. 1–2 mm. Capsule subclavate, ca. 1–2 × 0.3–0.6 cm.
Distribution: Nepal, E Himalaya, W Himalaya, Assam-Burma, E Asia, S Asia and SE Asia.
Altitudinal range: 300–1800 m.
Ecology: Epiphytic on tree trunks or large branches in open forests.
Flowering: May–June. Fruiting: July–October.