. Elements of botany. Plants. FERTILIZATION. 161 ears or none at all. The common ragweed, another monoecious plant, is remarkable for the great quantities of pollen which shake off it on to the shoes or clothes of the passer-by, and it is wind-fertilized. So, too, are the monoecious pines, and these produce so much pollen that it has been mistaken for showers of sulphur, falling often at long distances from the woods where it was produced. The pistil of wind-fertilized flowers is often feathery and thus adapted to catch flying pollen-grains (Fig. 143). Other char- acteristics of such flowers a
. Elements of botany. Plants. FERTILIZATION. 161 ears or none at all. The common ragweed, another monoecious plant, is remarkable for the great quantities of pollen which shake off it on to the shoes or clothes of the passer-by, and it is wind-fertilized. So, too, are the monoecious pines, and these produce so much pollen that it has been mistaken for showers of sulphur, falling often at long distances from the woods where it was produced. The pistil of wind-fertilized flowers is often feathery and thus adapted to catch flying pollen-grains (Fig. 143). Other char- acteristics of such flowers are the inconspicuous character of their flow- ers, which are usually green or green- ish, the absence of odor and of nectar, the regularity of the corolla, fig. of a Grass. and the appearance of the flowers «. ^ary; b, feathery stigma, , „ ,11 ,1 • adapted for wind-fertiliza- beiore the leaves or their occurrence tion. on stalks raised above the leaves. Pollen is, in the case of a few aquatic plants, carried from flower to flower by the water on which it floats. 198. Insect-Fertilized Flowers. — Most plants which require cross-fertilization depend upon insects as pollen-carriers,^ and it may be stated as a general fact that the showy colors and markings of flowers and their odors, all serve as so many advertisements of the nectar (commonly but wrongly called honey), or of the nourishing pollen which the flower has to offer to insect-visitors. Many insects depend mainly or wholly upon the nectar and the pollen of flowers for their food. Such insects usually visit during the day only one kind of flower, and therefore carry but one kind of pollen. Going straight from one flower to another with this, they evidently waste far less pollen than the wind or water must waste. It is therefore clearly advantageous to flowers to develop such adaptations as fit 1 A few are fertilized by snails ; many more by humming-birds and other Please note that these images ar
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
