Pollen as large as about 90–100 µm. In angiosperms, during flower development the anther is composed of a mass of cells that appear undifferentiated, except for a partially differentiated dermis. As the flower develops, four groups of sporogenous cells form within the anther. The fertile sporogenous cells are surrounded by layers of sterile cells that grow into the wall of the pollen sac. Some of the cells grow into nutritive cells that supply nutrition for the microspores that form by meiotic division from the sporogenous cells. In a process called microsporogenesis, four haploid microspores are produced from each diploid sporogenous cell
Pollen basket Pollen basket The pollen basket or corbicula (plural corbiculae) is part of the tibia on the hind legs of certain species of bees. They use the structure in harvesting pollen and carrying it to the nest or hive. Other species of bees have scopae instead. Bees in four tribes of the family Apidae, subfamily Apinae: the honey bees, bumblebees, stingless bees, and orchid bees have corbiculae. The corbicula is a polished cavity surrounded by a fringe of hairs, into which the bee collects the pollen; most other bees possess a structure called the scopa, which is similar in function, but