College of Agricultural Sciences Cooperative Extension Pennsylvania Pollinator Series 1. Animal Pollinated Plants and Their Importance

ince the dawn of human All flowering plants have in com- the help of external factors. In S time, flowering plants have mon highly specialized structures abiotic pollination, pollen is nurtured our bodies, challenged for sexual reproduction, called moved between flowers by wind our intellects, and uplifted our flowers. Flowers are complete or water. spirits. Flowering plants provide only when they contain sepals, In animal pollination, the plants rich and diverse sources of food, petals, and both female and male depend on animals to transfer medicine, clothing, paper, fiber, sexual parts. When flowers lack pollen from one flower to another. and construction materials. Our either the male or female sexual Most flowers use a concentrated ancestors developed critical parts, they are regarded as im- sugar solution, called nectar, to thinking in part by seeking to in- perfect, female or male flowers. lure animal pollinators. Pollina- crease their knowledge about Some plant species have both tors, such as bees, use the flow- how to use flowering plants. To- male and female flowers on the ers’ shapes, scents, and color day, we artistically design our same plant, while others have patterns as cues for accessing surroundings using the color, tex- male flowers on one plant and the nectar-producing glands. In ture and fragrance associated female flowers on another. their nectar quest, animals will with flowering plants. The flower’s female sexual part is brush parts of their bodies represented by the pistil, which against the anthers, the flower’s contains ovules, while the sta- pollen bearing parts. Pistil men, which produces pollen, Once attached to the animals represents the male sexual part. chemically, physically, and/or Depending upon how the pollen through electrostatic forces, the is transferred, there are three Stamens pollen granules will hitchhike a types of pollination: self- ride to another flower’s female pollination, abiotic pollination, and part, the pistil. There, stigma (the animal pollination. By ensuring pistil’s sticky upper part) will trap that the stamens touch the pistil, the pollen granules that come plants can self-pollinate without Pistil and stamens of mustard plant close to or in contact with it. Only if compatible, the pollen granules granules in order to set enough has been estimated to be as will grow tubes inside the pistil, seeds to form a healthy fruit. The much as 22 billion dollars (NRC, and fertilize the ovules, which will pumpkin pollen is heavy and 2007). However, this value is an become seeds. If a flower is in- sticky, and therefore it cannot be infinitesimal fraction of the value sufficiently pollinated, it will de- transferred by wind. Bees have of the pollination services pro- velop fewer seeds or drop, which only few hours in the morning for vided by animal pollinators to means fewer or no offspring. transferring the necessary pollen flowering plants, and subse- from the male flower to female quently to the environment. Ani- flower. If the bees are not present mal-pollinated plant species are or are in low numbers, the flowers significant sources of food and will abort or will set small and shelter for wildlife, and act as wa- misshaped fruit that will be flavor- ter and air filters, while helping to Animals, mostly insects, provide less and have a short shelf life. minimizing soil degradation by pollination services for a third of Many other crops can be wind conserving moisture and stabiliz- our food. Crop species and even pollinated, but they will produce ing soil. varieties of the same crop differ in more and better yields when bees Bibliography National Research Council. (2007). their requirements for animal pol- augment the pollination process. Status of Pollinators in North America. lination. Melons, cucurbit Washington DC: Board on Life Sci- In North America, the human diet squashes, and most pome fruits ences, Board on Agriculture and Natural is diversified and enriched with Resources, National Academy of Sci- have high pollination require- essential nutrients from more ences. ments and are entirely dependent Source: Asa Gray, The Elements of than 100 crops that benefit from Botany for Beginners and for Schools on insects. For example, a fe- insect pollination (NRC, 2007). (New York, Cincinnati, Chicago: Ameri- male pumpkin flower, de- can Book Co., 1887)86 The value of pollination services Source: S. G. Goodrich Animal Kingdom pending on variety, needs provided annually by wild and Illustrated Vol 2 (New York: Derby & several hundred pollen Jackson, 1859)2:557 managed bees to U.S. agriculture Written by Alexandru Surcică, Horticulture Program Assistant. Prepared by Alexandru Surcică, Molly Sturniolo, Centre County Master Gardener Coordinator, and Ginger Pryor, State Master Gardener Coordinator. Reviewed by Dr. Robert Berghage.

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