Title: The natural history of plants, their forms, growth, reproduction, and distribution; Identifier: cu31924057348165 Year: 1895 (1890s) Authors: Kerner von Marilaun, Anton, 1831-1898; Oliver, F. W. (Francis Wall), 1864-1951; Busk, Marian (Balfour) Lady, 1861-1941; Macdonald, Mary Frances (Ewart); Kerner von Marilaun, Anton, 1831-1898. Pflanzenleben. English Subjects: Botany Publisher: New York, H. Holt and Company Contributing Library: Cornell University Library Digitizing Sponsor: MSN

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Text Appearing Before Image: DISPERSAL BY WIND. 84& Steppes of the East produce smooth, ellipsoidal fruits about the size of a hazel-nut and so light that if one of them is laid on a person's open hand when his eyes are shut he does not perceive its presence. The extraordinarily small weight of these fruits is due to the fact that their structure includes a layer resembling the pith of the Elder. A fruit of Oachrys alpina measures 13 mm. in length and 10 mm. in thickness and weighs 0'07 grm.; another Oachrys fruit from Shiraz is 15 mm. long and 10 mm. thick and weighs only 0-06 grm. When fruits of this kind fall they are rolled along over the Steppe by the wind and only come to rest when they are caught in some crack in the parched clay soil or get lodged in a hole in a rock. A few Papilionacese also produce rolling fruits of the kind. One of the groups of species belonging to the Medick genus, of which Medicago scutellata (see fig. 464 ^) may be taken as a type, has pods which are spirally curled into round balls and which, when their seeds are ripe, detach themselves from their stalks and are rolled

Text Appearing After Image: Fig. 465.—Dispersion of fruits and seeds by the wind. Plantago Cretica. a Uttle way along the ground every time there comes a gust of wind. The same thing happens in the case of BlumenbacMa Hieronymi, a native of South America, belonging to the family Loasaceae. Although the spherical fruit of this plant has a diameter of 2-5 cm. it only weighs 0'34 grm. when thoroughly dried. As soon as the seeds are ripe the fruit-stalk withers and the round fruits, which are then left lying loose upon the ground, are rolled away by the gentlest breeze. If their career is stopped anywhere, and they get wetted by rain, the openings which are already formed in them become enlarged and a quantity of wrinkled seeds fall out. Paronychia Kapella (see fig. 468 % a plant of wide distribution in the floral area of the Black Sea, where it grows on dry rocky soil, brings small fruits to maturity in the height of summer, each of which is surrounded by silvery white membranous bracts. "When the season for the dispersion of these fruits arrives the entire tuft of fruits, which is in the form of a spherical glomerule, becomes detached from the branch on which it grows and lies lightly on the ground, where the least puff of wind imparts to it a swift rolling motion. Sometimes if the ground is uneven the rolling is converted into a hopping and springing motion, and occasionally such masses of fruit are raised by powerful gusts of wind and carried considerable distances through the air. In several species of Clover, such as Trifolium globosum, T. subterramum, and T. nidifieum (see fig. 4681") there are only a few perfectly VOL. II. lo* T

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