Editing Self-pollination (section)

== Occurrence ==
Few plants self-pollinate without the aid of pollen vectors (such as wind or insects). The mechanism is seen most often in some [[legume]]s such as [[peanut]]s. In another legume, [[soybean]]s, the flowers open and remain receptive to insect cross pollination during the day. If this is not accomplished, the flowers self-pollinate as they are closing. Among other plants that can self-pollinate are many kinds of [[orchid]]s, [[pea]]s, [[sunflower]]s and [[tridax]].  Most of the self-pollinating plants have small, relatively inconspicuous flowers that shed pollen directly onto the stigma, sometimes even before the bud opens. Self-pollinated plants expend less energy in the production of pollinator attractants and can grow in areas where the kinds of insects or other animals that might visit them are absent or very scarce—as in the Arctic or at high elevations.

Self-pollination limits the variety of progeny and may [[Inbreeding depression|depress plant vigor]].  However, self-pollination can be advantageous, allowing plants to spread beyond the range of suitable pollinators or produce offspring in areas where pollinator populations have been [[pollinator decline|greatly reduced]] or are naturally variable.<ref name="pmid25980327">{{cite journal |vauthors=Grossenbacher D, Briscoe Runquist R, Goldberg EE, Brandvain Y |title=Geographic range size is predicted by plant mating system |journal=Ecol. Lett. |volume=18 |issue=7 |pages=706–13 |year=2015 |pmid=25980327 |doi=10.1111/ele.12449 |bibcode=2015EcolL..18..706G |s2cid=833417 }}</ref>

Pollination can also be accomplished by [[cross-pollination]]. Cross-pollination is the transfer of pollen, by wind or animals such as insects and birds, from the anther to the stigma of flowers on separate plants.