Epiphytic or lithophytic sympodial herbs; rhizome short or long and creeping, often branched, slender to quite stout. Pseudobulbs 1-noded, clustered or distant, stem-like or more often swollen, ± angled in cross-section, arising from rhizome at intervals, 1–2-leaved (rarely more) at the apex. Leaves mostly coriaceous or fleshy or rarely thin-textured, small to large. Inflorescences arising from base of pseudobulb or rarely from node on rhizome, 1–many-flowered, racemose or rarely umbellate. Flowers ± fleshy, often not opening widely, mostly small in African species, white, cream or green to orange and purple. Dorsal sepal subequal and less commonly much shorter than lateral sepals; lateral sepals free or rarely adnate, united at base to column-foot to form a ± prominent mentum. Petals mostly much smaller than sepals. Lip often much smaller than sepals, hinged to end of column-foot, often highly mobile, often fleshy, ligulate and curved, mostly entire. Column short, often winged and with apical stelidia; anther small, 2-chambered, with 4 pollinia in pairs; column-foot mostly incurved, united to base of lateral sepals.
Dorsal sepal free, erect, or spreading; lateral ones oblique at the base and adnate to the foot of the column, forming a chin, erect or spreading, free or rarely connate, sometimes larger than the dorsal one. Petals mostly smaller and narrower than the sepals. Lip contracted at the base, and articulated to the foot of the column, mostly recurved, usually small and more or less fleshy, glabrous, ciliate, minutely toothed or barbate; side lobes mostly small or obsolete. Column erect, mostly very short; apex with two or rarely four variously shaped teeth; base produced into a longish foot. Anther terminal operculate, incumbent, usually somewhat depressed, 2- or rarely 1-celled; pollinia waxy, normally 4, but usually more or less connate in pairs, unappendaged or rarely cohering by a viscid exudation. Capsule ovoid or oblong. —Herbs with more or less creeping rhizomes. Pseudobulbs sessile in the axil of a sheath, ovoid-oblong, 4-angled or subcompressed, rarely absent, 1 or 2-leaved. Scapes arising from the base of the pseudobulbs, simple, their bases bearing numerous sheaths. Flowers in spikes, racemes or umbels, rarely solitary; rhachis slender or thickened, but not flattened. Bracts often small, occasionally larger and imbricate.
Epiphytic or lithophytic herb with sympodial growth.Rhizomes creeping, often woody, sometimes branched.Pseudobulbs each comprising 1 internode (representing the main axis ofa sympodial branch), clustered or spaced out along the rhizome, 1–2(3)-leaved at the apex.Leaves mostly coriaceous or fleshy, rarely thin-textured.Inflorescences arising from base of the pseudobulb, racemose or rarely umbellate, (1)few- to many-flowered.Rhachis sometimes swollen or flattened; flowers white, cream, yellow, green, orange or purple, ± fleshy.Sepals usually free and subequal, the lateral sepals united at the base to the column foot to form an obscure mentum.Petals usually smaller than the sepals.Lip often much smaller than the sepals, hinged to end of the column foot, usually motile, often fleshy and tongue-like, sometimes fringed with long or short hairs.Column short, usually with apical lateral extensions (stelidia), and often winged.Pollinia 2 or 4 in 2 pairs.
Epiphytic, occasionally lithophytic, or rarely terrestrial herbs. Sympodia arising from or (well) above one subterminal nodes from a previous sympodium. Basal part of each sympodium with three to many nodes forming a creeping or patent rhizome enveloped in cataphylls when young. Last node of each sympodium usually swollen into a pseudobulb (rarely with lower nodes swollen as well), sometimes not or hardly swollen, apex 1–3-leaved (6–12-leaved in B. sect. Chaseella). Leaves usually persistent, sometimes deciduous, duplicate, inarticulate, usually petiolate, thinly herbaceous to coriaceous, usually glabrous. Inflorescences usually heteranthous, consisting of modified sympodia sprouting from or (well) above nodes along rhizome, ofter close to pseudobulbs, each with several bract-bearing nodes, one- to many-flowered, apical or along distal part of rhizome. Rachis usually a peduncle, but sometimes swollen into a spindle-shaped body, or widened and bilaterally flattened with flowers either inserted on flat side, or along the edges; usually glabrous, or papillose, rarely pubescent; floral bracts appressed to reflexed, caducous or persistent. Flowers either distichous or spirally arranged, (partly) resupinate or not, opening either simultaneously or in succession, (almost) closed to widely open. Sepals free to adherent to connate (the dorsal to laterals, the laterals along their upper or lower margins, or all three), margins entire to erose to fimbriate, glabrous to papillose to ciliate, surface glabrous to papillose or hirsute; lateral sepals equal to dorsal sepal or distinctly different in length, shape, and surface ornamentation, and fused to column foot along basal part of their lower margins. Petals free, similar to sepals or not. Labellum usually with the base hinged to column foot by a flat strip of tissue allowing free movement of labellum parallel to bilateral plane of symmetry of flower, sometimes (partly) immobile because the strip of tissue is too short or too thick to allow movement, or because the labellum and column foot are fused; undivided to trilobed, margins entire to denticulate to fimbriate, glabrous to papillose to ciliate to vesiculose, adaxially with or without longitudinal ridges, more rarely with transverse ridges. Column usually ending in two stelidia; often winged along lower margins, column foot present; anther connected to apex of column by a thin strip of tissue, bilocular, pollinia two or four, the inner pair as large as the outer or (much) smaller, usually waxy, hard to soft, sometimes with stalks: caudicles, hamular or tegular stipes; stigma concave, transversely elliptic to a longitudinal slit, separated from anther by seam-like, thin or fleshy rostellum; viscidium usually inconspicuous, semi-liquid. Ovary and pedicel glabrous or covered in hairs; node at the base of pedicel level with attachment of subtending bract or (well) above it. Capsule obovoid to ellipsoid to subglobose, stalked or not, sometimes winged or triangular in cross-section.
Bulbophyllum comprises about 2200 species and is widely distributed from continental tropical Africa, the Comoros, Madagascar, the Seychelles, Reunion and Mauritius (about 200 species), India, Nepal, Bhutan, China, Taiwan, Thailand, Malaysia, Indonesia, the Philippines, New Guinea, Australia, New Zealand and the tropical Pacific islands as far east as Tahiti (about 1700 species) to the Neotropics (about 100 species). The main centres of diversity are Madagascar (200 species) and New Guinea (600 species).
Hist. Orchid. [Fl. Iles Austr. Afr.]: tab. gen., figs. 93–97 (1822), nom. conserv. —Vermeulen, Orchid Monogr. 2: 1–300 (1987).
Orch. Iles Austr. Afr., t. 93–97 (1822), nom. conserv.
Benth. et Hook. f. Gen. Pl. iii. 501.
Orch. Iles. Austr. Afr. tt. 93-97 (1822); F.T.A. 7: 22, including Megaclinium Lindl. Nom. cons.