Bijdr. (1825) 355
Leafless monopodial epiphytes. Stem very short. Inflorescence lateral from the stem, a few- to many-flowered raceme, with the flowers opening in succession; peduncle sometimes hairy, rachis usually very short, sometimes hairy or warty. Flowers minute to medium-sized, often ephemeral, resupinate or not. Sepals all three connate or free. Petals connate to the sepals or free, usually similar to the dorsal sepal, but often somewhat narrower. Lip spurred, not mobile. Column-foot absent. Rostellum very short to long and beak-like. Pollinia 4, solid, caudicles absent, stipe present, viscidium present.
Tropical Africa (one species), Sri Lanka, tropical continental Asia, Japan, Malaysia, Indonesia, the Philippines, Papua New Guinea, Australia, east to Tahiti. About 170 species; in New Guinea c. 90 known species, but many more species probably remain to be discovered.
Epiphytes in lowland and montane forest, often in the canopy on thin twigs; also on solitary trees, fruit-trees, large shrubs (even in city gardens), etc.
Taeniophyllum is the largest and most diverse genus among the leafless monopodial orchids, which include genera like Chiloschista (Asia), Dendrophyllax (America), and Microcoelia (Africa and Madagascar). In these genera the plants consist of nothing but a radiating cluster of roots; the stem is usually very short. Normal leaves are sometimes developed but short-lived. In New Guinea only the genera Taeniophyllum and some species of Microtatorchis show this type of growth, although the genus Chiloschista may be expected to occur here as well, since it is found in Australia and the Moluccas. Microtatorchis differs from Taeniophyllum in having two instead of four pollinia, otherwise it can hardly be distinguished from Taeniophyllum section Sepalocodon. Most of the species of Taeniophyllum in New Guinea are very poorly known and are hardly ever found in cultivation. We have been unable to identify several of the species that were available to us in the form of photographs or specimens and we must assume that these represent undescribed taxa. Considering that these plants are difficult to spot in the field and moreover have short-lived flowers it is likely that many species still await discovery. Some of the New Guinea members of this genus have broad, ribbon-like flattened roots and are by far the largest of this type of orchid in the world. Taeniophyllum clearly has its main area of diversity in New Guinea, where the range in size and shape of the flowers and the number of species are far greater than elsewhere.
Schlechter divided the genus into six sections, which are at least useful into dividing this rather large genus into manageable groups. We must await molecular studies to assess the phylogeny of the genus. Since the type species of Taeniophyllum (T. obtusum Blume) belongs to Schlechter's section Trachyrhachis this should now be called Taeniophyllum.
Key to the sections of Taeniophyllum
1a Ovary hairy ... section Trachylepus
1b Ovary glabrous ... 2
2a Sepals connate, at least at the base; tip of the lip often with a backwards-pointing tooth ... section Sepalocodon
2b Sepals free; tip of the lip without a backwards-pointing tooth ... 3
3a Inflorescence very short, almost without peduncle; rachis more or less warty ... section Taeniophyllum (synonyms: sect. Trachyrachis, sect. Liberosepalum)
3b Inflorescence elongated, with a well-developed peduncle; rachis glabrous ... 4
4a Lip distinctly 3-lobed ... section Loboglossum
4b Lip entire ... 5
5a Rostellum elongated, beak-like ... section Rhynchanthera
5b Rostellum very short ... section Brachyanthera