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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    contain but few florets; those of Eupatorium cannabinum have five, which open one after another in the course of 5-8 days. Younger and older flowers are therefore always close together. The styles are rather different from those of other Composites, being divided almost half-way down into two long threadlike branches which bear the stigmatic tissue only on their lower portions. The rest of the branch is thickly studded with short bristles, the aforesaid sweeping hairs. The styles are parallel and folded together as long as they are inclosed in the anther-tube (see fig. 2942), and they remain closed for some time after they have elongated and Fig. 294.—(leitonogamy with adherent pollen. 1 Crossing of the stylar branches of neighbouring florets in the capitulum of Eupatorium cannabinum. 2 Longitudinal section through the upper part of a floret of Eupatorium-, the two stylar branches are parallel and inclosed by the anther-tube, which is again surrounded by the corolla-tube. 8 Umbel of Chcerophyllum aromaticum; the truly hermaphrodite flowers are open, the pseudo-hermaphrodite male flowers are still closed. 1 The same umbel; the true hermaphrodite flowers haue lost their pollen; the male flowers are now open, and their anthers drop pollen on the stigmas of the hermaphrodite flowers. All the figures somewhat enlarged. pushed their way above the anthers. During the elongation the sweeping hairs brush the pollen from the anther-tube, and it then adheres in abundance to the outer side of each style-branch. This condition, however, does not continue for long. The stylar branches soon diverge at an angle of 40-50°. The branches of adjacent styles now cross one another like rapiers, and when the pollen is detached from the sweeping hairs it falls on to the mature stigmatic tissue. The closed pollen-covered stylar branches, as they emerge from the anther-tube, come in contact with the divergent branches of older neighbouring florets, and thus the pollen is transferred to the stigmatic tissue of the latter.