Grosourdya, Reichenbach, 1864

Kocyan, Alexander & Schuiteman, André, 2013, New combinations in Aeridinae (Orchidaceae), Phytotaxa 161 (1), pp. 61-85 : 65

GROSOURDYA

Grosourdya Reichenbach (1864: 297) . Type species: Grosourdya elegans Rchb. f.

Ascochilopsis Carr (1929: 21) Type species: Ascochilopsis myosurus (Ridl.) Car.

Ascochilus Ridley (1896: 374) Type species: Ascochilus siamensis Ridl.

In our analysis, Grosourdya ( Fig. 1C ) is paraphyletic unless the species of Ascochilus , Ascochilopsis and certain species of Biermannia (not including the type of the genus) are included in it. In this alliance, it is demonstrated again that floral characters previously used in taxonomy of this subtribe, such as the presence of a column foot, spur, or motile lip, are not reliable indicators of affinity or generic status. Species of Grosourdya are all small, short-stemmed plants with leaves arranged in a fan; wiry and stiff inflorescences are finely muricate, and their ephemeral flowers open in succession.

The rare Peninsular Malaysian taxa Biermannia flava (Carr) Garay , B. laciniata (Carr) Garay and B. sarcanthoides (Ridl.) Garay are misplaced in Biermannia on account of the inflorescence morphology as they lack the sharply delimited cavities on the rachis. However, they would probably be misplaced in Grosourdya as well, due to the abbreviated, glabrous inflorescences and narrow tepals. Carr may well have been correct in assigning them to Chamaeanthus . They differ from the type species of Chamaeanthus , C. brachystachys Schltr. , mainly in the relatively shorter column-foot. As this is a variable character in several genera in Aeridinae , e.g. Brachypeza , Grosourdya and Phalaenopsis , probably not much weight should be attached to this difference.

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).