The Periodic Acid-Schiff (PAS) reaction was used to test for the presence of starch, and Sudan black was applied to detect neutral lipids (lipid drops) during anther development in Ipomoea cairica. Starch was observed in sporogenous and anther wall cells. Prior to meiosis in microspore mother cells (MMCs), starch was not evident, although small lipid drops appeared. A substantial amount of starch accumulated in the epidermal and endothecium cells, but starch and lipid drops were not identified in the tapetum. At the tetrad stage, starch appeared in microspores, and the amount of starch remained constant in anther cells. Early in the microspore stage, the tapetum degenerated, starch remained in the microspores, and lipid drops were completely lost. A large and conspicuous vacuole was formed in the microspores and lipid drops reformed in the cells at the late microspore stage. Following microspore division, the vegetative cell of bicellular pollen grains was filled with starch and lipid drops, and the inner middle layer degenerated. Finally, at anthesis, lipid drops and starch constituted the stored nutritive material in the mature pollen.