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 28 wind pollination, male DHJanzen101043.jpg high resolution
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| Grasses (Poaceae) and sedges (Cyperaceae) are almost entirely wind-pollinated, both in the tropics and extra-tropical regions. Corn, a large grass, is no exception. Here the cluster of male flowers (tassle) at the top of the corn plant releases its pollen into the wind, and as it gradually falls it spreads to the female flowers lower down on other plants. It avoids some self-pollination by having its stigmas be receptive later than when the first pollen is released, but pollen is still being released when the stigmas do become receptive, so self-pollination is possible if cross-pollination has not occurred already. Associated with being wind-pollinated, grass pollens are generally either of very low nutritional value to bees, or actually toxic to bees. And it should be of no surprise that grass inflorescences are not brightly colored as are the flowers of animal-pollinated flowers, and generally do not produce nectar. | ||
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