Scanning electron micrograph of a dehiscing anther of goosegrass, Galium aparine. The picture shows pollen grains (yellow) that have been shed by the anther at the picture centre (blue). Pollen is the male microspore; upon contacting a receptive female stigma, it divides to produce a vegetative cell and a generative cell. The latter divides to produce sperm cells, that are conveyed to the ovary of the receiving flower through a tube produced by the vegetative cell. This leads to fertilisation of an egg cell and thus to the growth of a seed. Goosegrass is a common arable and garden weed. The plant is covered with hooks, that enable it to climb surrounding vegetation. The flower is protandrous; its pollen matures before the stigma is receptive, favouring cross-pollination by insects. The seeds can be roasted, ground, and used to make a low caffeine coffee subsitute. Mag x 50 at 10x8