. Botany for high schools. Botany. SEED DISPERSAL 20I the ground " right side up/' , with the radicle of the embryo downward. In the dandelion the flower stem elongates just as the seed is ripening, so that the head is lifted up where the currents of air readily reach it. The bristles cf the pappus in many composites, at first straight, turn out at nearly right angles, like the spokes of a tiny wheel, so that it is more effective as a float. The so-called tumble weeds are rolled on the ground by the wind to great distances, and the seeds are scattered by the way. Some of these are the
. Botany for high schools. Botany. SEED DISPERSAL 20I the ground " right side up/' , with the radicle of the embryo downward. In the dandelion the flower stem elongates just as the seed is ripening, so that the head is lifted up where the currents of air readily reach it. The bristles cf the pappus in many composites, at first straight, turn out at nearly right angles, like the spokes of a tiny wheel, so that it is more effective as a float. The so-called tumble weeds are rolled on the ground by the wind to great distances, and the seeds are scattered by the way. Some of these are the light, much branched grasses, which when ripe and dry are broken off by the wind and swept along on t he ground. The res- urrection " plant {Ly- copodium) is another example of a plant which is distributed by the wind. As it dries up during droughts it curls into a rounded mass, the roots are torn from the ground, it rolls along in the wind, and with the advent of rains takes root and grows Fig. 162. Lactuca 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 Atkinson, George Francis, 1854-1918. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
