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 beetle but pollen is a major part of its diet. Several members of the Nitidulidae are similarly referred to as pollen beetles. In particular, practically all the species in the genus "Meligethes" are called pollen beetles. Of these the most notorious is probably the one now accepted as being properly called "Meligethes aeneus"/"Brassicogethes aeneus". It is called the "Brassica pollen beetle", "Rape pollen beetle" and similar names, because it first became prominent as a pest of such crops in the first quarter of the 20th century. Many species in the family Oedemeridae are similarly called "pollen beetles". For example, the Southern