Bijdr. (1825) 297
Sympodial epiphytic or occasionally terrestrial plants without or with very short rhizomes. Stem slender, elongated, sometimes branching, not or slightly fleshy, with many closely spaced leaves in two rows. Leaves sheathing at the base, glabrous, deciduous, duplicate, thin-textured or sometimes more fleshy. Inflorescence lateral or terminal, a raceme, a panicle or carrying a single flower. Flowers small to very small, resupinate. Lateral sepals more or less connate, forming a mentum. Petals free, about as long as and often fairly similar to the dorsal sepal. Lip without spur, not mobile, often with a backwards projecting appendage. Column-foot present. Pollinia 6, solid, seemingly with two caudicles, but these are in fact modified, sterile pollinia; stipe absent, viscidium present.
Tropical continental Asia, Malaysia, Indonesia, the Philippines, Papua New Guinea, Pacific islands, east to Tonga. About 90 species; in New Guinea c. 40 species.
Usually on tree trunks and thick branches in lowland and montane forest, often growing in shady positions.
A genus of almost fern-like plants, due to the regular foliage evenly distributed along slender stems. The very inconspicuous flowers have a prominent 'chin' (mentum), and (unique among Asian orchids) six pollinia. Schlechter (Schlechter, 1911-1914) proposed a subdivision into sections based on inflorescence characters, as follows:
Appendicula ('Eu-Appendicula') - inflorescences lateral, very short;
Chaunodesme - inflorescences mainly terminal, peduncle short, rachis elongated;
Pododesme - inflorescences terminal or lateral, with long peduncle enveloped in scale-leaves;
Oligodesme - inflorescences 1-flowered, terminal;
Chromatodesme - inflorescences dense, with short peduncle, and conspicuous white or pink bracts (not occurring in New Guinea).
In all of these sections the lip has a more or less distinct lobe-like basal appendage, while the column has a pointed, bidentate rostellum.
To these can be added two sections which Schlechter regarded as good genera:
Chilopogon - inflorescences terminal, with short peduncle and long distichous bracts, lip without basal appendage;
Cyphochilus - inflorescences terminal or also lateral, rostellum broad, deeply emarginate.
Regrettably, Hallé in 1977 chose to typify the genus Appendicula with A. alba Blume, a member of Schlechter's section Chaunodesme, rather than with A. reflexa, which is the best-known representative of Schlechter's Eu-Appendicula. If accepted, this typification would imply that sect. Chaunodesme would have to be called sect. Appendicula, while sect. Eu-Appendicula would require a new name. Indeed, this was proposed by Kores (1989: 120), who renamed the latter to sect. Stenodesme. However, we would like to argue that Hallé's typification was apparently done in ignorance of Schlechter's sectional division and therefore is to be rejected as being more or less automatic (i.e. by randomly choosing one of the species originally included in Appendicula by Blume). Instead we propose to typify the genus Appendicula with A. reflexa Blume so that with the minor modification of the name Eu-Appendicula to Appendicula Schlechter's names can still be used. To what extent these sections are monophyletic groups is another matter that has to await detailed DNA analyses, which are probably not forthcoming any time soon.