. Introduction to botany. Botany. Flowers. 177 the younger flowers to the stigmas of the older, or vice versa in case of proterogyny. In dimorphic flowers the pollen from short anthers would quite certainly be deposited by insects on the stigmas of the short pistils, as in going from B to A, Fig. 91. Adaptations for cross fertilization are perhaps best seen in the various adjustments of flowers t6 the agents which are to transport the pollen and deposit it on the stigma. These agents, as has been stated, are wind, in- sects and other ani- mals, and water. 127. Adaptation to Wind. — Those flow-
. Introduction to botany. Botany. Flowers. 177 the younger flowers to the stigmas of the older, or vice versa in case of proterogyny. In dimorphic flowers the pollen from short anthers would quite certainly be deposited by insects on the stigmas of the short pistils, as in going from B to A, Fig. 91. Adaptations for cross fertilization are perhaps best seen in the various adjustments of flowers t6 the agents which are to transport the pollen and deposit it on the stigma. These agents, as has been stated, are wind, in- sects and other ani- mals, and water. 127. Adaptation to Wind. — Those flow- ers which depend upon the wind for transporting the pol- len are characterized by protruding stamens and a relatively large expanse of stigmatic surface; this is well shown by Indian corn, whose staminate flowers surmount the plant and send forth numerous pendent stamens which offer their pollen to the wind. The long silken styles which protrude beyond the husks of the pistillate inflorescence, or ear, present a large surface for arresting the pollen as it is being carried about by winds. The pines, poplars, and willows illustrate the same thing in somewhat different ways. The pollen of the pine is borne in great abundance in the staminate catkins (see Fig. 92), and each grain is provided with two balloon-like expansions containing air, which contribute to its lightness. Fig. 92. Staminate catkin of the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Stevens, William Chase, 1861-. Boston, D. C. Heath & Co.
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