Ceratostylis Blume,
Bijdr. (1825) 304
Sympodial epiphytes with tufted habit, or less often with pendulous elongated rhizomes. Pseudobulbs consisting of one internode, very slender, resembling a petiole, or almost absent, 1- or rarely 2-leaved at the apex. Leaves not sheathing at the base, glabrous, dorso-ventrally flattened or terete, deciduous, duplicate, leathery. Inflorescence terminal, usually very short, carrying a single flower, often occurring in clusters. Flowers small to very small, resupinate or not. Lateral sepals connate, forming a mentum that often resembles a spur. Petals usually narrower than the sepals. Lip without spur, not mobile. Column at the apex with two lobes. Column-foot present. Pollinia 8, solid, caudicles absent, stipe absent, viscidium present.
Distribution
India, tropical East Asia, Malaysia, Indonesia, the Philippines, Papua New Guinea, Pacific islands, east to Vanuatu (not in Australia); about 80 species.
Distribution in the Philippines
Luzon (Ilocos Norte, Mt. Province, Ifugao, Benguet, Isabela, Nueva Vizcaya, Nueva Ecija, Pangasinan, Pampanga, Zambales, Bataan, Laguna, Rizal, Quezon, Tayabas, Sorsogon, Camarines), Mindoro, Panay, Negros, Leyte, Mindanao (Zamboanga, Lanao, Misamis, Bukidnon, Surigao, Agusan, Davao, Cotabato), Basilan; 12 species.
Habitat
Epiphytes in lowland and montane forest, often in shady positions.
Notes
With very few exceptions the members of this genus are insignificant plants with tiny, dull-coloured flowers produced just below the base of the leaves. Perhaps the most notable exception is Ceratostylis retisquama, a commonly cultivated Philippine species with large bright red flowers and better known by its synonym C. rubra.