File:Flying seeds 3.jpg

Identifier: naturalhistoryof02kern Title: The natural history of plants, their forms, growth, reproduction, and distribution; Year: 1902 (1900s) Authors: Kerner von Marilaun, Anton, 1831-1898 Oliver, Francis Wall, 1864- Macdonald, Mary Frances Ewart Busk, Marian Balfour, Lady Subjects: Botany Publisher: London, Blackie Contributing Library: NCSU Libraries Digitizing Sponsor: NCSU Libraries

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Text Appearing Before Image: parachute, with the nut lian^^iiigfreely below at the end of a string, like an enterprising balloon-gymnast. From the fruits and seeds equipped with parachutes we pass to those which areembedded in masses of wool or in envelopes of silky hairs, and are thereby enabled 858 THE DISPERSION OF SPECIES BY MEANS OF FRUITS AND SEEDS. to remain poised in the air. The hairs arise either from the surface of the seed-coat{testa), as in the Cotton trees {Bomhax and Gossypium; see figs. 470 ^ and 470^), orelse they spring from the base of the seed, as in Poplars and Willows (Populusand Scdix; see p. 423, figs. 318 ^ and 318*; p. 424, fig. 319 and fig. 471 ^°). In theBulrush {Typha; see fig. 471 *) they take their rise from the pedicels of the fruits,and in several Ranunculaceae (e.g. Anemone sylvestris; see fig. 470 2) from theachenes themselves. In other cases they arise from the floral-leaves, as, for instance,in the Cotton-grass {Eriophorvbiii] see fig. 471 ^), where the structure which repre-

Text Appearing After Image: Melica Balansce. ^ Calamagrostis Epigeios; nat. size. 3 The same m;speciosus. 6 Epilohium collinum. Clematis Flammula. Dispersion of fruits and seeds by the wind. * Geum rnontanum, 6 JEschyyianthui sents the perianth is transformed into delicate hairs, and in Trifolium plumosum,where the fruiting calyx is wrapped in wool. In many Grasses the glumes arebeset with extremely fine hairs (e.g. Melica and Calamagrostis; see figs. 472 ^2^),in Micropus, of the Compositse, long hairs project from the scales of the involucreand envelop the entire capitulum in a flocculent mass, and in the Venetian Sumachor Wig-plant (Rhus Cotinus) the stalks of abortive flowers are covered with awoolly down, which serves for the dispersion of the fruits, whose stalks are usuallyfree from wool. Lastly, we have the cases where the fruits or seeds are keptsuspended in the air for a more or less prolonged period by means of special hairytails. Either the seeds are tailed at both ends, as in ^schynanthus (see fig. 4

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