Dispersal of 11 dominant grass species in the savanna of southern Botswana was investigated. The dispersal is autochorous, anemochorous and epizoochorous independent of the life-cycle (annuals, perennials). Dispersal distances were estimated experimentally. Anemochorous species with a plume-like spikelet such as Chloris virgata and Enneapogon cenchroides have a low rate of descent ( < 1 m s 1) and a low Reynold number (100-110). Nevertheless they can only be transported up to 13 m from the originating infructescence at a wind velocity of 10 m s-x. Therefore, the majority of the disseminules remained near the parent plant. By analysing the seed pool under the canopy of trees of Dichrostachys cinerea epizoochorous species such as Tragus berteronianus were dominant at the cattle resting sites under trees. The results are discussed in relation to the three seed dispersal hypotheses and the model of selective interaction of dispersal, dormancy, and seed site as adaptions to variable environments.