REVISION OF THE RACEMOSA GROUP OF THE GENUS PASPALUM (POACEAE, PANICOIDEAE, PANICEAE)

Ten species of group Racemosa of genus Paspalum are treated in this work, including two new species, Paspalum rugulosum Morrone and Zuloaga and P. soukupii Carbono. Group Racemosa is defined as annual plants of medium to high altitudes that inhabit moist places and have the following characteristics: culms decumbent, rooting and branching at the lower nodes, blades flat, ovate-lanceolate, lanceolate to linear-lanceolate, inflorescences with several to many deciduous racemes, rachis of the racemes foliaceous, spikelets uniseriate or biseriate, with or without an upper glume and upper anthecium cartilaginous or crustaceous. Anatomically the species of group Racemosa are characterized as being Kranz, MS type, with peculiar distinctive Kranz cells in the mesophyll. Relationships of this group with other infrageneric taxa of Paspalum are discussed. A key to the species, as well as an anatomical description of the group and photomicrographs, morphological description of the species, and distribution maps are presented.