Growth form models within the genus Paspalum L (Poaceae, Paniceae)

Based on a set of morphological features of vegetative axes, some basic patterns ('models') are characterized which represent reference points in order to describe the variation of growth forms within the genus Paspalum. This character set comprises duration, differentiation of short and long internodes, number of such internodes, growth direction, presence of adventitious roots, position and relative strength of branches and leaf type. The 19 models ae grouped as follows: A) annual, hapaxanthic species, PU) perennials with unbranched culms, PB) perennials with branched culms, and S) stoloniferous monopodial grasses. Morphological relationships are discussed and some probable evolutionary trends are outlined.