A genus of small-flowered orchids, generally with rather simple, uniform flowers, having the basal part of the lip parallel with the column, and the remaining part making a right angle with the basal part. The genus is interesting because of its nearly cosmopolitan distribution and in that it contains epiphytic as well as terrestrial species. Normally the individual species are either epiphytic or terrestrial. Species of Liparis are not often cultivated, being mostly fairly inconspicuous, frequently with green or brownish flowers. Many, however, have a subtle charm and most are quite easy to grow. They will usually flower almost 'automatically' from the developing young shoot.
Schlechter (1911-1914) proposed a detailed subdivision of the genus that will undoubtedly be found to require modification when DNA analyses of a sufficiently large number of species are performed. His sections, however, are at least useful as an aid towards identification, and in most cases they do seem to group related species together. On the other hand, some very similar taxa, such as Liparis altigena Schltr. and Liparis ovalis Schltr. are not only assigned to different sections, but even to different subgenera, just because in the former the leaves are not articulated, while in the latter they are articulated with the leaf-sheaths. It is unlikely that this reflects the true phylogeny of these species.
While we recognise that there is undoubtedly an element of artificiality in this classification we have nevertheless attempted to fit all the New Guinea species of Liparis in Schlechter’s system. Our main rationale is that this subdivision makes it easier to identify specimens in the absence of a key to the species. Some of the names we use are different from Schlechter's for nomenclatural reasons. As in Dendrobium and Bulbophyllum, Schlechter’s sections are so to speak better than his subgenera, and we have not adopted the latter. We consider it likely that sect. Platychilus should be merged with sect. Platyglossum, while sect. Genychilus should probably be merged with sect. Genyglossum. Van Royen (1979) subsumes sect. Hologlossum under sect. Platyglossum, but this requires further study, in our opinion.
Most of the sections of Liparis were typified by P. van Royen (1979). Unfortunately he made the mistake of typifying sections Genyglossum and Genychila with the same species, Liparis genychila Schltr. The type of the former should clearly be Liparis truncicola Schltr., the only species originally included by Schlechter in sect. Genyglossum.
We refer to our general remarks in the Introduction on the nomenclature of sections and subgenera.
Some of the sections are more distinctive than others, and there have been proposals to raise the more easily recognised ones to generic rank. The section Distichae is an obvious candidate for this treatment. As a genus it should be called Stichorkis. However, we prefer to keep section Distichae within the genus Liparis, as species with very similar floral and vegetative morphology occur elsewhere in the genus (e.g. Liparis torricellensis Schltr).
Key to the New Guinea sections of Liparis.
1a. Leaves plicate or not, soft herbaceous, convolute (at least seemingly so in plicate-leaved taxa, and clearly so when the leaves are not plicate), not articulated with the leaf-sheath == 2
1b. Leaves not plicate, more or less leathery, duplicate, either or not articulated with the leaf-sheath or pseudobulb == 3
2a. Pseudobulbs 2-leaved. Leaf not plicate, attached below the pseudobulb and enveloping this == sect. Rachidibulbon
2b. Shoot 1- to few-leaved; leaves plicate, arising from the upper part of the pseudobulb == sect. Elatae
3a. Inflorescence seemingly basal (in fact heteranthous) -- Pseudobulbs hardly developed, reduced to a minute conical swelling, 1-leaved. Leaves erect, at the very base articulated == sect. Choriostachys
3b. Inflorescence terminal == 4
4a. Leaves not articulated with the sheath or pseudobulb, gradually withering away when dead, remnants of the veins for a long time remaining on the apex of the pseudobulb == 5
4b. Leaves articulated with the sheath or pseudobulb, leaving a clean scar when falling off == 7
5a. Pseudobulbs with a few grass-like leaves distributed along the stem == sect. Pleiophyllum
5b. Pseudobulbs 1-leaved at the apex == 6
6a. Lip entire == sect. Platychilus
6b. Lip 3-lobed == sect. Genychilus
7a. Inflorescence with closely spaced, distichous bracts. Flowers opening in succession, usually one-by-one ==sect. Distichae
7b. Floral bracts not distichous, usually not closely spaced. Flowers several to many opening at the same time, gradually more opening == 8
8a. Lip 3-lobed near the base == sect. Genyglossum
8b. Lip not lobed near the base == 9
9a. Lip abruptly bent downwards near the middle, often notched or bilobed at the apex. Usually epiphytes == 10
9b. Lip only bent at the base, entire. Usually terrestrials == sect. Platyglossum
10a. Lip at apex rounded to acute, entire. Peduncle strongly flattened and winged or terete == sect. Hologlossum
10b. Lip at apex bilobulate, or truncate and irregular. Peduncle terete == sect. Cestichis (syn. sect. Blepharoglossum Schltr.)
Liparis contgains XXX species; in New Guinea 77 species and 2 varieties:
Liparis spectabilis var. dischorensis
Liparis truncicola var. oblanceolata