Volume 4

The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours.

  • Kerner von Marilaun, Anton, 1831-1898.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours. Source: Wellcome Collection.

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    or the teeth of a comb. This is particularly the case if the stigma is lobed, the lobes being fairly large and spoon-shaped, cup-shaped, or like a funnel, and if the insect on entering only touches the edge of the stigmatic lobes with the pollen-laden part of its body. This is the case, for example, in the flowers of many Gentians, Narcissi, Gladioli, and Cro- cuses (e.g. Gentiana Ba- varica, Narcissus poeticus. Gladiolus segetum, Crocus sativus; cf. figs. 279 4> 5-7). The pollen, when depo- sited, is held between the papillae of the stigma like dust on velvet pile or on a brush or comb; nor is it absolutely necessary that the stigmatic papillae should be sticky, though, of course, the power of retention is thus obviously increased. Some stigmas are beset with transparent papillae, and at the same time are rendered very sticky by a layer of fluid secreted by the surface cells of the stigma, as, for example, in the Sundew (Drosera; cf. 279 10 and 279 n). But such cases are rare on the whole. Usually the velvety stigmas and those beset with long pa- pillae are not sticky, the viscosity being restricted to wart-like and granulated Fig. 281.—Evening Primrose ((Enothera biennis). (After Baillon.) stigmas. Examples of plants with very sticky stigmas are furnished by the Umbelliferae, the Rhododendrons, Bearberries, Ericas, Whortleberries and Cranberries, Winter Greens and Polygonums, the Deadly Night- shade, and Bartsias. A sticky stigma often terminates a thin threadlike style either as a small disc or head, and is the more conspicuous on account of the glitter of its sticky coating than because of its size. In the flower of the Mahogany-tree (Swietenia Mahagoni; see fig. 282 3) it has the form of a disc, in Azalea procumbens (see fig. 279 17) it is slightly convex with five projecting ridges radiating from the