Porpax elaidium (Lindl.) Schuit., Y.P.Ng & H.A.Pedersen, Bot. J. Linn. Soc. 186: 199 (2018).
Homotypic Names:

Bulbophyllum elaidium Lindl., J. Proc. Linn. Soc., Bot. 6: 127 (1862).
Phyllorkis elaidum (Lindl.) Kuntze, Revis. Gen. Pl. 2: 677 (1891).
Stolzia elaidium (Lindl.) Summerh., Kew Bull. 17: 557 (1964).
Epiphyte or lithophyte grass; stems thickened into 2-leaved pseudobulbs, up to 4 mm long and 3 mm wide. Leaves opposite, ovate to elliptical, 5-7 mm long and about 3 mm broad. Basal inflorescences, 1-flora. Translucent greenish to whitish flowers; epichile 3.5-4 mm long and 2-2.5 mm wide, distinctly trilobed, with narrowly triangular median lobe, longer than lateral lobes which are broadly triangular.
This species was known only in Príncipe; it had never been reported in São Tomé. It presents, on this island, a distribution area concentrated in secondary forests and plantations that surround the Roça de Bombaím. In Príncipe, it is known only on Pico Papagaio and Morro Fundão. Although it is most often epiphytic, it sometimes has a lithophytic lifestyle. It likes medium to large diameter branches located all the way up the trees. It is sometimes seen on the trunk of trees, but only if it is covered with other epiphytes. It also shows a great affinity with other epiphytes, in particular with mosses. It forms populations that can number hundreds of individuals grouped in a dense carpet covering large areas. This orchid is found in a wide variety of habitats. It likes both sunny habitats and those receiving only low light intensity. We can, for example, see it on the branches of small diameter located in the shade, but also, on the base of the small shrubs of the low altitude ridges of Príncipe. This orchid is small in size and mainly frequents the canopy of trees; it is therefore difficult to observe.
Liberia, Nigeria, Rio Muni, Príncipe, São Tomé.
Orchid Monographs Vol 2 - A Taxonomic Revision of the Continental African Bulbophyllinae Vermeullen 1987; Flora of West Tropical Africa, Kew Bull. 17: 567 (1964).; Droissart, V., Simo, M., Sonké, B., Cawoy, V. & Stévart, T. (2009). Le genre Stolzia (Orchidaceae) en Afrique centrale avec deux nouveaux taxons. Adansonia, III, 31: 25-40.; Szlachetko, D.L. & Mytnik-Ejsmont, J. (2015). Orchidaceae of West-Central Africa 2: 1-300; Szlachetko, D.L. & Mytnik-Ejsmont, J. (2015). Orchidaceae of West-Central Africa 2: 1-300
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