What Pollinates Dull Green Grass Flowers?

Grass Flower Characteristics

• Grass flower size, color and form vary between grass species, but there are common features among all grasses. Grasses carry their flowers on thin stems held as high up as physically possible on the plant. The flowers are dull in color, greenish yellow or creamy white, and lack petals, nectar or fragrance, which would be strategies to allure pollinating insects and birds. The grass flowers are tiny but numerous. The pollen shed from the flowers is lightweight and tiny yet, released in tremendous amounts.

Anemophily

• Practically all grass species around the world rely on the wind for pollination, a condition scientifically termed anemophily. While some grass species are visited and pollinated by various insects or animals, this is rare. Wind is abundant throughout habitats although it may vary by season or time of day. Moreover, wind is not affected by temperature or habitat destruction, unlike insects and animals. Grasses are, therefore, freer to reproduce without relying on other living things. However, in situations where wind doesn't occur at an opportune time or frequency, pollination can be negatively affected.

Flower Structure

• Because grasses do not need large colorful petals or big blooms to attract animals or to act as a landing pad for insects, their flower structure evolved much differently than plants, such as palms, orchids, lilies or roses. A grass' flower is called a floret and occurs in a wispy cluster called a spikelet. Instead of petals, a bud-like structure called a lemma encases the floret's sex organs. The lemma opens to reveal the male stamens that shed pollen into the air. The female stigmas branch outward at the floret's base.

Organ Modification

• In many other flowering plant species, the flower contains very structured sex organs, usually in the middle of the flower. Such a configuration isn't necessary for simple wind pollination. The stamens in grass florets are on long, floppy filaments that whip in the wind, releasing high amounts of pollen grains. To catch as many of these wind-carrying grains as possible, the female stigma structures in grass florets are wide and feather-like, acting like a net to catch pollen from random breezes. In other flowering plants, the stigma is often small and sticky, for targeted capture of pollen from insect movements.