. The classification of flowering plants. Plants. 254 FLOWERING PLANTS [CH. Unisexual flowers are the rule, the male and female often occupying different parts of the same system ; for instance, a few females occur at the base of the branches, while the upper part is thickly crowded with males, or, as in Raphia Ruffia, the branches of the spike bear female flowers in the lower, male in the upper half On the other hand, flowers of the two sexes may be mixed, as in Geonoma, where the bracts on the fleshy spike each shelter a group of three flowers, thus: male, female, male (fig. 120, B). In this
. The classification of flowering plants. Plants. 254 FLOWERING PLANTS [CH. Unisexual flowers are the rule, the male and female often occupying different parts of the same system ; for instance, a few females occur at the base of the branches, while the upper part is thickly crowded with males, or, as in Raphia Ruffia, the branches of the spike bear female flowers in the lower, male in the upper half On the other hand, flowers of the two sexes may be mixed, as in Geonoma, where the bracts on the fleshy spike each shelter a group of three flowers, thus: male, female, male (fig. 120, B). In this case the two male flowers appear in suc- cession and then the female, so that the spike is for the time being unisexual. There may be considerable differ- ence in size between the two flowers, as in Bor^assus, where the enormous female flowers contrast strongly with the minute male. The flowers are regular and conform to the very general monocotyledonous formula, P 3 + 3, A 3 3, G 3 for the exceptional hermaphrodite, while the stamens are rudi- mentary in the female and the carpels in the male. The inconspicuous peri- anth is tough and persistent, leathery or fleshy in consistence, and green to yellow or white in colour. The sepals are generally smaller than the otherwise similar petals (fig. 125, A). Sometimes a whorl of stamens is wanting, or there is an indefinite number. The powdery pollen is produced in great quantity, escaping in clouds from the large male spikes. Wind-pollination is probably most general, though some Palms, Sabal and Chamaedorea, are said to be ento- mophilous. The inflorescence certainly has a sweet smell, while the great mass of flowers is a conspicuous object. Self- pollination is excluded where the male and female flowers are close together on the same spike by the well-marked protandry. Fig. 120. Geonoma. A. Portion of fleshy spadix, embedded in the surface of which are 3-flowered cymes (see B); a male flower is shewn protruding beyond each fl
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplants, bookyear1904
