. Botany of the living plant. Botany. APPENDIX A 535 individual flower is already known in the case of the Sunflower, by the study of its development (Chapter XIII., p. 239, Fig. 188). Each flower is there seen in the normal position, in the axil of a bract; it consists of 5 petals, 5 stamens, and 2 carpels. The transverse section of the flower approaching maturity shows these parts arranged as in a floral diagram. The odd petal is anterior ; the stamens alternate with the petals, and the carpels are antero- posterior (Fig. 188, viii.). The ovary is inferior, unilocular, and contains one
. Botany of the living plant. Botany. APPENDIX A 535 individual flower is already known in the case of the Sunflower, by the study of its development (Chapter XIII., p. 239, Fig. 188). Each flower is there seen in the normal position, in the axil of a bract; it consists of 5 petals, 5 stamens, and 2 carpels. The transverse section of the flower approaching maturity shows these parts arranged as in a floral diagram. The odd petal is anterior ; the stamens alternate with the petals, and the carpels are antero- posterior (Fig. 188, viii.). The ovary is inferior, unilocular, and contains one ovule. This structure O is fundamental for all Compositae (Fig. 441). ^-;-"f*^~;-^ As in similarly crowded inflorescences (for in stance the cyathium of the Spurges, p. 515), the crowding brings with it reduction of the individual flowers, but it does not go so far in the Compositae as in the Spurges. The most usual modification is tlic reduction of the calyx, its protective function having devolved upon the involucre. Sometimes it is absent, as in the Daisy ; or it may be re- presented by two or three teeth, as in Bidens 'â '°- â *''⢠; (Fig. 238,£). But most frequently it is developed °''' ' ('jf/terVkhlorT''"^''"'' as a means of fruit-dispersal, taking the form of a "pappus" composed of bristles, which spread like a parachute (Fig. 254, p. 290). The bract subtending each flower is often abortive, as in the Dandelion and Daisy. The flowers themselves though typically hermaphrodite are liable to become unisexual by abortion. These are all features of reduc- tion, following on the aggregation of the flowers in the compact inflorescence. The florets may develop in three different ways, though all are fundamen- tally of the same construction having the general formula, S, (5, or o or x), P. 5, A. ^, G. (2). The firsttype is radially symmetrical, with five equal petals. This is probabl)' the original type, and is characteristic of the florets
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