识别要点：Bulbophyllum hamatum resembles B. omerandrum in free lateral sepals, petals bearing fimbriate-ciliate margin, and fleshy recurved ligulate lip, but differs in hooked or falcate stelidia, caudate dorsal sepal and petals, and ovoid column wings.
形态特征：Epiphytic or lithophytic herb. Rhizome creeping, 2 mm in diam., rooting from base of pseudobulbs. Pseudobulbs 1–7 cm apart on rhizome, narrowly pyriform to subcylindric, 1–2.5 cm, 0.3–1.2 cm in diam., with a terminal leaf. Petiole1–2 cm; leaf oblong, 3–8.5 × 0.7–1.6 cm, thick, leathery, base cuneate, apex obtuse and retuse, mid-vine concave adaxialy, convex abaxialy. Scape arising from base of pseudobulb, erect, usually 5–9 cm; condensed raceme 2–4-flowered; peduncle slender, ca. 1 mm in diam., 2 or 3 tubular sheaths, placed sparsely; floral bracts ovate, cymbiform, 8–12 mm. Pedicel and ovary 1.2–2 cm, densely purple spotted. Flowers yellowish white. Dorsal sepal broadly ovate, 6–10 × 5 mm, apex long acuminate to caudate, margin entire, 4–5-veined; lateral sepals usually free, narrowly falcate-lanceolate, 16–22 × 5 mm, base adnate to column foot, margin entire, twisted near base and divergent, apex acuminate. Petals ovate or ovate-triangular, 5 × 4 mm, tip caudate with a thread 2–3 mm, margins finely erose to deeply lacerate distally, 3-veined; lip recurved, ligulate, ca. 6 mm, fleshy, base attached to end of column foot by a mobile joint, apex obtuse and apiculate , sparsely finely papillate on both sides. Column ca. 5 mm, with ovoid wings at upper part; foot curved, ca. 4mm, with free part ca. 3 mm; stelidia hooked or falcate, ca. 2 mm; anther cap comblike on apical margin; pollinia 4, in 2 pairs.
