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 DNA barcoding atmospheric pollen originating from illegal cannabis farms were successfully detected by scientists which in the future could allow law enforcement officials to narrow down the search areas for illegal farms. Due to the hardy structure of pollen which has evolved to survive being transported sometimes great distances while keeping the internal genetic information intact, the origin of pollen found mixed in ancient substrates can often be determined through DNA barcoding. Honeybees carry pollen as well as the nectar used in their production of honey. For food quality and safety concerns it is important to understand the plant providence of human-consumed