. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. LEGUMINOSAE 323 flower mechanism as similar to that of V. Cracca, except as regards the nature of the brush arrangement. For here the style (2^ mm. long) bears two brushes, immediately beneath the stigma. They are completely separate, about 1 mm. long, and respectively situated internally and externally. The inner brush consists of a single row of short hairs slanting upwards, while the outer one is composed of hairs which radiate obliquely upwards towards t
. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. LEGUMINOSAE 323 flower mechanism as similar to that of V. Cracca, except as regards the nature of the brush arrangement. For here the style (2^ mm. long) bears two brushes, immediately beneath the stigma. They are completely separate, about 1 mm. long, and respectively situated internally and externally. The inner brush consists of a single row of short hairs slanting upwards, while the outer one is composed of hairs which radiate obliquely upwards towards the stigma, and enclose a plate- like depression. The anthers dehisce when the flowers have attained a considerable size, shed their pollen into a swelling at the tip of the carina, and are then retracted. Access to the nectar is more difficult than in V. Cracca, for the petals are thicker and firmer, the calyx-tube surrounds their claws for a greater distance, and the vexillum is tumid at the entrance to the nectar-passage, which is bounded by it and the alae. In addition to this, the arms of the alar levers, which depress. Fig. 106. Vicia septum, L. (after Herm. Miillcr). (i) Flower seen from the front. t2) The same, after removal of calyx and vexillum; seen from above. (3) The same, after the alae also have been removed ; seen from above. (4) The same, seen from the side. (5) Style with brushes and stigma, seen from the side. (6) Brushes and stigma, seen from above. (7J Stamens and pistil of a bud. References as in Fig. 105. the carina, are relatively shorter than in V. Cracca. Hence only powerful bees (Bombus, Anthophora) are able to suck legitimately and effect crossing. The flies and Lepidoptera which so often steal nectar from V. Cracca, sucking legitimately but without benefit to its flowers, are here excluded, and this is a distinct advantage. On the other hand, Bombus terrester regularly perforates the flowers from the side and steals the nectar, although it possesses
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