. Notes on the life history of British flowering plants. Botany; Plant ecology. GERANIACE^ 125 The large-flowered species are protandrous, the inner row of stamens generally opening first. The flowers are much visited by insects and dependent on them for fertilisation. The species with smaller flowers are less visited by insects and less dependent on them. Honey is richly secreted by five nectaries, generally at the outer side of the base of the inner stamens. It is protected from rain and from creeping insects by a number of fine hairs just above the base of the petals. The presence of these
. Notes on the life history of British flowering plants. Botany; Plant ecology. GERANIACE^ 125 The large-flowered species are protandrous, the inner row of stamens generally opening first. The flowers are much visited by insects and dependent on them for fertilisation. The species with smaller flowers are less visited by insects and less dependent on them. Honey is richly secreted by five nectaries, generally at the outer side of the base of the inner stamens. It is protected from rain and from creeping insects by a number of fine hairs just above the base of the petals. The presence of these hairs on the petals of G. sylvaticum started Sprengel on his clas- sical study of flowers. He argued that the great Creator would have made nothing in vain, and therefore that even these tiny hairs must be of some use. In the large-flowered species, as, for instance, in G. pratense (Figs. 69, 70), all the stamens open, shed their pollen, and wither away before the pistil comes to maturity. The flower cannot therefore fertilise itself, and depends entirely on the visits of insects for the transference of the pollen. In G. pyrenaicum, where the flower is not quite so large, all the stamens ripen before the stigma, but the interval is shorter, and the stigma is mature before all the anthers have shed their pollen. It is therefore not absolutely dependent on insects. In G. molle, which has a still smaller flower, five of the stamens come to maturity before the stigma, but the last five ripen simultaneously with it. Lastly, in G. pusillum, which is least of all, the stigma ripens even before the stamens. Thus, then, we have a series more or less dependent on insects, from G. pratense, to which they are necessary, to G. pusillum, which is. Fig. 69.—Geranium Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original wor
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Keywords: ., bookauthorlub, bookcentury1900, bookdecade1900, booksubjectbotany
