Synonyms: Schistotylus APNI* Papillilabium APNI*
Description: Epiphytic or rarely epilithic herbs, monopodial; roots mostly aerial.
Leaves scattered along the stem, 2 or more per shoot, distichous, conduplicate.
Inflorescence racemose, several-flowered, lateral; flowers resupinate. Sepals free, similar. Lateral petals free, about as long as, or slightly shorter than sepals. Labellum free, attached to tip of column foot; lamina 3-lobed, with a prominent backward-pointing spur, which bears a callus on its anterior wall. Column lacking free filament and style; column wings apparently absent. Column foot longer or shorter than column. Anther incumbent, cap-like. Pollinia 4, waxy. Stigma entire. Rostellum prominent, projecting forward or decurved, ventral.
Distribution and occurrence: World: 5 species, endemic Australia. Australia: Qld, N.S.W. (3 species), Lord Howe Island (1 species).
The monotypic genera Papillilabium and Schistotylus have been merged with Plectorrhiza, in line with morphological and molecular sequence evidence cited by Clements et al. (2019)
Text by P. H. Weston, updated by M.A.M. Renner (Oct 2019) Taxon concept: Clements MA, Jones DL, Banks DP (2019) Notes on Australasian orchids 4: subtribe Aeridinae. Australian Orchid Review 84(2): 29.
| Key to the species | |
1 | Internodes separating leaves long, leaves widely spaced, stems longer than the leaves. Labellum distinctly trilobed | 2 |
| Internodes separating leaves short, leaves tufted, stems shorter than the leaves. Labellum indistinctly trilobed | 3 |
2 | Stems erect, leaves fleshy, broadly elliptic, up to 20 mm wide | Plectorrhiza erecta |
| Stems pendulous or pendant-procumbent, leaves leathery, linear to narrow elliptic, at most 15 mm wide Back to 1 | Plectorrhiza tridentata |
3 | Labellum bearing four yellow-green pigment spots, lacking a false pouch at base of midlobe. Anther cap purple-red pigmented. Column surrounding stigma white to pale green. | Plectorrhiza beckleri |
| Labellum bearing two yellow pigment spots, with a false pouch at base of midlobe. Anther cap unpigmented. Column surrounding stigma bright pink-purple. Back to 1 | Plectorrhiza purpurata |
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