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Genus Platylepis

Genus Platylepis

Platylepis A.Rich., Mém. Soc. Hist. Nat. Paris iv. (1828) 34; Orch. Iles Fr. et Bourb. 39. t. 6.

Synonyms:

  • Genus Coralliokyphos Fleischm. & Rech., Denkschr. Kaiserl. Akad. Wiss.
  • Genus Moerenhoutia Blume, Coll. Orchid. (1858) 99

Sympodial terrestrial plants. Stem elongated. Leaves few, sheathing at the base, glabrous, dorso-ventrally flattened, not articulate, convolute, herbaceous. Inflorescence terminal, a raceme. Flowers small, resupinate, usually green or reddish with a white lip. Sepals free. Lateral sepals patent. Petals free, about as long as the dorsal sepal, usually cohering at the apices. Lip without spur, not mobile, concave, laterally constricted below the middle, inside with two keels and two basal tufts of hairs, outside along the margins with more or less well-developed crest-like ornamentation. Column-foot absent. Pollinia 2, sectile, caudicles present, stipe absent, viscidium present. Stigma 1.

In New Guineagenus Platylepis contains the following 4 species:

Platylepis constricta
Platylepis geluana
Platylepis intricata
Platylepis zeuxinoides


Key to the species of Platylepis in New Guinea

1a. Lip with 2 keels adaxially on the mesochile ............................................................................................... 2
1b. Lip without keels (possibly with thickened midnerve) .................................................................................. 3

2a. Keels thin, plate-like, glabrous. Mesochile of lip without callosities on abaxial surface .... Platylepis constricta
2b. Keels thick, densely pubescent. Mesochile of lip with large, armour-like callosities with lobed-crenate
margins on the abaxial surface ......................................................................................... Platylepis intricata

3a. Lip adaxially at the base on either side with a tuft of subulate, sometimes branching, hair-like papillae. Petals
with denticulate margins .............................................................................................. Platylepis zeuxinoides
3b. Lip adaxially at the base on either side with a rounded, densely verruculose-rugose appendage. Petls with
entire margins ................................................................................................................ Platylepis geluana


Moluccas, New Guinea and further east to Tahiti. About 10 species; in New Guinea 5 species.

Terrestrial in hill and montane forest.

  • Howcroft, N.H.S. 1984. A guide to the Monocotyledons of Papua New Guinea. Part 4. The Orchidaceae (in part). Pp. 79-80, fig. 44. PNG University of Technology, Lae.
  • Pridgeon, A. M., P.J. Cribb, M.W. Chase & F.N. Rasmussen (Eds.). 2003. Genera Orchidacearum, Vol. 3: Orchidoideae (Part 2), Vanilloideae 137-139, fig. 160.1. (as Platylepis, in part).
  • Schuiteman, A. & E.F. de Vogel, Malesian Orchid J. 9 (2012, publ. 2011) 17
  • Subfamily Orchidoideae
  • Tribe Cranichideae
  • Subtribe Goodyerinae
  • Genus Platylepis

Platylepis is distinguished from Goodyera by the basal constriction of the lip, by the presence of two keels inside on the lip, and by having two separate tufts of hairs rather than a single large patch of hairs in the basal part of the lip.

We have decided to follow Genera Orchidacearum (Ormerod in Pridgeon et al. 2003) in treating Moerenhoutia as a synonym of Platylepis. We now agree that the differences between the two (mainly the lateral flange on the column) are too minor, and the similarities too striking, to be able to regard them as two independently evolved entities that happen to be extremely similar. The disjunction in the distribution of the genus: Africa, Madagascar and the Comoros in the west, the Maluku, New Guinea and the Pacific in the east, is remarkable. Platylepis sensu stricto is from the western part of the distribution area, Moerenhoutia from the eastern part.

Species included in this database:

Platylepis constricta
Platylepis geluana
Platylepis intricata
Platylepis lamellata
Platylepis zeuxinoides


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Genus Platylepis

Moerenhoutia cf. zeuxinoides (Schltr.) Schltr., inflorescences, photo N.E.G. Cruttwell, March 1985, PNG, Mt. Gahavisuka, 2250 m

Genus Platylepis

Platylepis constricta (J.J.Sm.) J.J.Sm., floral analysis, drawing J.J. Smith, based on von Römer 687

Genus Platylepis

Platylepis constricta (J.J.Sm.) J.J.Sm., lip, column, anther, and pollinia, drawing J.J. Smith, based on von Römer 687

Genus Platylepis

Platylepis lamellata Schltr., drawing R. Schlechter in Repert. Spec. Nov. Regni Veg. Beih. 21 (1923) t. 22, fig. 73