Pollen cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm cells. Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower. Pollen grains come in a wide variety of shapes, sizes, and surface markings characteristic of the species (see electron micrograph, right). Pollen grains of pines, firs, and spruces are winged. The smallest pollen grain, that of the forget-me-not ("Myosotis" spp.), is around 6 µm (0.006 mm) in diameter. Wind-borne pollen grains can be
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