The pollen grains of 14Acaciaspecies from different parts of Sudan are described. The number of grains in each polyad is 16 except inA. albidawhich has 32 grains in each polyad. The pollen diameter, and pore number and diameter, follow a geographical pattern of variation both between species and topoclines within species. Pollen grains are smaller with fewer and smaller pores in arid northern Sudan than humid southern Sudan. Patterns of morphological variation in sculpturing of the exine, which are constant for species, are reported.