Bijdr. (1825) 368
Sympodial epiphytic or rarely terrestrial plants with very short to somewhat elongated rhizomes. Stems elongated, with few to many internodes, sometimes swollen into slender, flattened pseudobulbs. Leaves few to many, arranged in two rows, sheathing at the base, glabrous, deciduous, duplicate, thin-textured but rather stiff; leaf-sheaths usually with black or brown margins. Inflorescence terminal [at least seemingly so] or rarely lateral, very short, 1- or few-flowered, usually produced in head-like clusters. Flowers small, resupinate or not, white or yellowish, sometimes with purple or yellow markings on the lip. Sepals free. Petals free, about as long as but much narrower than the dorsal sepal. Lip without spur, but sometimes sac-shaped at the base, not mobile, usually clearly divided into a cup-shaped basal part and a flat apical part. Column-foot indistinct or absent. Pollinia 8, solid, caudicles absent, stipe absent, viscidium present. Ovary usually with a few scattered scale-hairs.
Seychelles, tropical Asia, Malaysia, Indonesia, the Philippines, Papua New Guinea, Pacific islands, east to Samoa. About 60 species; in New Guinea c. 40 species.
Usually epiphytic on tree trunks and thick branches in lowland and montane forest.
Members of this genus are as a rule easily recognised by the head-like clusters of small whitish flowers at the apex of the stems. The black or brown margins of the leaf-sheaths are also highly characteristic, although they are paralleled in some species of Phreatia. Agrostophyllum is almost unknown in cultivation, but quite common in the wild. Schlechter (Schlechter, 1911-1914) divided the species into four sections, as follows:
Appendiculopsis - leaves numerous, very small, abruptly contracted between the blade and the sheath;
Agrostophyllum - leaves otherwise, rhizome not as in sect. Oliganthe, inflorescences head-like or solitary;
Oliganthe - rhizome much elongated, stem-like, pendulous, otherwise as sect. Agrostophyllum;
Dolichodesme - inflorescences not arranged in a head, arising from the elongated leafless apical part of the stem, otherwise as sect. Agrostophyllum.
This subdivision is still useful for identification purposes, but it is probably not a natural one, in that species with morphologically very similar flowers can be found in sect. Agrostophyllum (e.g. Agrostophyllum uniflorum), sect. Oliganthe (e.g. Agrostophyllum superpositum) and sect. Dolichodesme (e.g. Agrostophyllum earinoides).