Thrixspermum Loureiro (1790: 519)

Kocyan, Alexander & Schuiteman, André, 2014, New combinations in Aeridinae (Orchidaceae), Phytotaxa 161 (1), pp. 61-85 : 75

Thrixspermum Loureiro (1790: 519) . Type species: Thrixspermum centipeda Lour.

Dendrocolla Blume (1825: 286) . Type species: Dendrocolla hystrix Blume.

Orsidice Reichenbach (1854: 93) . Type species: Not designated.

Cylindrochilus Thwaites (1861: 307) . Type species: Cylindrochilus pulchellus Thwaites.

Ridleya (Hook.f.) Pfitzer (1900: 16). Type species: Ridleya notabilis (Hook.f.) Pfitzer.

Cordiglottis Smith (1922: 95) Type species: Cordiglottis westenenkii J.J.Sm.

Cheirorchis Carr (1932: 40) Type species: Cheirorchis breviscapa Carr.

Thylacis Gagnepain (1932: 599) . Type species: Not designated.

Cordiglottis was separated from Thrixspermum based on its ‘non-saccate lip, long bent column, the nearly equal pollinia and the large stigma’ ( Smith 1922) and terete or laterally flattened leaves. However, the discovery of new Cordiglottis species made differences in floral characters appear less reliable; in addition, several Thrixspermum species with terete leaves are now known. Hence, a distinction based on morphological characters is difficult to maintain. Moreover, our molecular systematic studies found Cordiglottis deeply nested in Thrixspermum . With our current knowledge of the genus, Cordiglottis cannot be kept separate unless Thrixspermum is split into several smaller genera. We prefer, however, a more broadly circumscribed Thrixspermum ( Fig. 1F ). All species have ephemeral flowers, often lasting only a few hours.

Figures

FIGURE 1. Selected flower images of the newly combined taxa to illustrate floral diversity among Aeridinae. A, Brachypeza unguiculata; B, Dimorphorchis breviscapa; C, Grosourdya myosurus; D, Phalaenopsis difformis; E, Renanthera caloptera; F, Thrixspermum breviscapum; G, Robiquetia punctata; H, Robiquetia minimiflora; I, Renanthera porphyrodesme; J, Taeniophyllum javanicum; K, Trachoma phillipsii; L, Trichoglottis biglandulosa; M, Trichoglottis ventricularis. Photographs by A. Kocyan (A, B, D, E, G–M), P. O’Byrne (C) and P.T. Ong (F).