SPRING FLOWERS 119 



its branches, and the branching of the flowering shoot or in- 

 florescence having been mentioned above, it remains to describe 

 the flower itself (Fig. 61). It will be found to be constructed 

 on an essentially similar plan to that of the Buttercup. On 

 the outside are three greenish-yellow sepals, which enclose the 

 flower-bud when small. Within the calyx come eight to twelve 

 narrow strap-shaped petals, greenish below but bright shining 

 yellow on the upper surface. Each petal has a small scale on 

 its upper surface close to the attachment, and nectar is secreted 

 in the little pocket formed by this. Within the petals come a large 

 number of stamens, each with a yellow stalk supporting a relat- 

 ively broad anther. The carpels 

 are inserted separately, though 

 closely crowded, on the summit 

 of the conical floral receptacle. 

 Each consists of a flattened green 

 ovary bearing at its summit the 



L -- r -IT FIG. 6 1. Flower of Lesser Celandine, 



rough stlgmatlC Surface. If a cut in half. (After Baillon.) 



carpel is carefully opened with the 



tip of a sharp knife or scalpel it will be found to contain a single 



ovule attached close to the base of the cavity of the ovary. 



As in the Buttercup, all the parts of this flower are inserted 

 separately on the enlarged conical end of the flower stalk or floral 

 receptacle, and stand in undisturbed succession on this. The 

 calyx is lowest, while the pistil, composed of the group of separate 

 carpels, occupies the summit of the receptacle. 



The flowers close at night or in bad weather, but when widely 

 open in the sunshine are very conspicuous, and are visited by many 

 insects, chiefly small flies and bees. These may come in search 

 either of the pollen, of which there is abundance formed in the 

 numerous stamens, or of the nectar, which is hidden in the 

 nectaries but easily reached. Since the stamens and stigmas 

 are usually mature at the same time, there is every possibility 

 that the flower may be pollinated with its own pollen, though 

 in passing from flower to flower an insect may effect cross- 

 fertilisation. 



Many of the flowers do not develop fruits, though these can 

 usually be found on careful search. The fruit is composed of 



