. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. 136 INTRODUCTION Veronica Chamaedrys will serve as a typical example. The bright blue flowers are streaked with darker lines, and ornamented in the middle with a paler nectar- guide. They are united into moderately conspicuous inflorescences, and are homogamous. The style with its terminal stigma projects obliquely downwards. Fig. 51. Veronica latifolia^L., a Hover-fly Flower. A. Flower seen exactly from the front (x 7), B. The same seen from the side, after
. Handbook of flower pollination : based upon Hermann Mu?ller's work 'The fertilisation of flowers by insects' . Fertilization of plants. 136 INTRODUCTION Veronica Chamaedrys will serve as a typical example. The bright blue flowers are streaked with darker lines, and ornamented in the middle with a paler nectar- guide. They are united into moderately conspicuous inflorescences, and are homogamous. The style with its terminal stigma projects obliquely downwards. Fig. 51. Veronica latifolia^L., a Hover-fly Flower. A. Flower seen exactly from the front (x 7), B. The same seen from the side, after half of it has been removed (X 7); j, sepals ;/, petals ; »;, nectary; «, stamens; J/, stigma. out of the middle of the flower where nectar is produced, while the two stamens diverge from each other to right and left. The filaments are narrowed at their bases and can therefore be easily turned inwards. Small variegated Syrphidae (Ascia podagrica, Melanostoma mellina, and others) first hover for a second in front of the flower, delighting in its beautiful colour, and then settle on its centre, thus coming into contact with the projecting stigma. In order to obtain a firm hold, they first grasp the filaments with their fore-legs, and immediately afterwards with their middle and hind-legs, and before one has time to see it they have unconsciously brought together the two stamens under the ventral side of the abdomen, and dusted that region with pollen, which is de- posited on the stigma of the next flower the) visit (Fig. 50). This striking floral mechanism also occurs in a few other species of the genus Veronica, though in some of them it is not so highly perfected, V. longifolia, montana, latifolia (=urticifolia). (See Fig. 51.) Our native species of Circaea present the same adaptation to hover-flies, for it is only insects of this kind that bring their floral mechanism into action in the proper Please note that these images are extracted from scanned page images t
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