Revision of the South American Genus Otachyrium (Poaceae, Panicoideae)

A review of this genus of seven species is provided with descriptions and illustrations of each. Of these species, four are described as new: O. aquaticum, O. grandajlorum, O. piligerum, and O. seminudum. Two, O. pterigodium and O. versicolor, are already known in the literature, and one, O. succisum, is a new combination. In addition to its short, subequal glumes, remarkable peculiarities of this panicoid genus are the enlarged palea of the lower staminate floret and the chartaceous, dark and shining or sometimes opaque and greenish, upper hermaphrodite floret, both of which are united at maturity.