Diaspore weight and dispersal were measured in 229 plant species of the central Australian arid zone. The frequency distribution of log diaspore sizes was unimodal, as has been observed for other habitats. the quantity of reserve (embryon plus endosperm) stored in the seed was related to the weight of the dispersal unit. Reserve weight was greater for woody species than for herbaceous species. Within each growth form, there was no clear relationship between perenniality and reserve weight. Most graminoids were wind dispersed, and elaiosomes for and dispersal were more common among the woody species (...)