Buffel grass (Cenchrus ciliaris), an important subtropical forage species, was grown under a range of environmental conditions; growth and development were followed by a series of regular harvests. The rates of plant growth and development increased with increasing levels of solar radiation up to the highest levels received (approximately 700 cal/cm2/day). The distribution of dry matter between the various plant organs was relatively unaffected by changes in temperature or mineral level ; differences in partitioning apparently occurred with respect to light intensity, root growth being restricted at the time of flower development at the lower intensities. The implications of the results are discussed with emphasis on possible differences between subtropical and temperate grass species.