The status and typification of Thrasya paspaloides Humb., Bonpl. & Kunth (Gramineae)

Thrasya paspaloides Humb., Bonpl. & Kunth (Gramineae, Paniceae) is considered with respect to its status as the type species of its genus. Errors in Kunth's original description are identified and analysed in the light of opinions formed by Trinius and Nees; and by analogy with plants from collections subsequent to the type collection; morphological characters are discussed, and data provided for a comparison with the related species T. thrasyoides (Trin.) Chase and T. trinitensis Mez, with which T. paspaloides is commonly confused. The geographical distribution of the three species is examined, together with the habitat. The conclusions are used to support proposal of a modification of the description of T. paspaloides and the selection of a lectotype.