. Cyclopedia of American horticulture, comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers, and ornamental plants sold in the United States and Canada, together with geographical and biographical sketches. Gardening. 1558. Cypripedium. st, staminodium; a, anther; 5, stigma. I 1569. Selenipedium caudatum. st, staminodium; a, anther; 5, 3-lobed stigma. The anther lies above the rostellum, within a depres- sion or anther-bed (Fig. 1570, a). Its cells vary from 2-4 or 8. In nearly all the Orchids the pollen coheres in masses or
. Cyclopedia of American horticulture, comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers, and ornamental plants sold in the United States and Canada, together with geographical and biographical sketches. Gardening. 1558. Cypripedium. st, staminodium; a, anther; 5, stigma. I 1569. Selenipedium caudatum. st, staminodium; a, anther; 5, 3-lobed stigma. The anther lies above the rostellum, within a depres- sion or anther-bed (Fig. 1570, a). Its cells vary from 2-4 or 8. In nearly all the Orchids the pollen coheres in masses or poUinia (Fig. 1570, p), the number of pollen masses corresponding to the number of anther cells. Often the viscid substance uniting the pollen grains is prolonged into a stalk (caudicle), which ex- tends beyond the anther and comes into contact with the viscid substance secreted by the rostellum, which forms an adhesive disk by means of which the pollinia become attached to insects. In many Orchids the outer layer of the rostellum itself separates by a dissolution of the underlying cells, and thus forms a stalk (stipe), which becomes attached to the poUinia by means of the product of the dissolved cells. Whatever its origin, the stalk, with its viscid disk, forms one of the most important parts of the mechanism by means of which pollen is transported from flower to flower, insuring cross-pollination of the group. The details of the mechanism by which this is accomplished have been beautifully explained by Darwin in his classical work, "The Various Contrivances by which Orchids are Fer- tilized by ; The relation of the parts of the flower to one another is often greatly changed by the peculiar growth of the floral axis. This is convex in the very young stages of development, but it soon becomes cup-like and finally tubular, inclosing the ovary. Special lateral outgrowths. Please note that these images are extracted from scanned page images that may have been d
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