54 THE BOOK OF NATURE STUDY 



green flower-stalk widens out below the calyx and corolla into an 

 elongated green body which resembles an inferior ovary. This 

 is really only a cup-shaped development of the receptacle of the 

 flower, as can be seen by splitting a flower in half (Plate, Fig. B), 

 when the separate carpels will be found springing from the inner 

 surface of the cup. The calyx, corolla, and stamens spring from 

 the margin of the cup. 



The five sepals are green, dotted with red glandular hairs on 

 the outside, and covered with a growth of short silky hairs on the 

 inner surface. They do not stand at exactly the same level, but 

 form a spiral, the outermost sepals having rudimentary pinnae 

 on one or both margins. The five large and delicate petals, 

 which alternate with the sepals, are more or less rounded and widen 

 out from a narrow attachment. This is yellowish ; the lower part 

 of the petal is almost white, while nearer the edge it becomes a 

 delicate pink. Immediately within the regular corolla come the 

 numerous stamens, which also stand on the margin of the cup- 

 shaped receptacle. Both filaments and anthers are yellow, so 

 that the flower has a conspicuous yellow centre. The anthers 

 stand at about the same level, since the filaments of the outer 

 stamens are longer and more inclined, while those of the inner ones 

 are shorter and more erect. In the centre of the flower is the 

 group of stigmas projecting from the narrow opening of the cup 

 formed by the receptacle. In a flower which has been cut in 

 half it is easy to see that the carpels are distinct from one another, 

 and stand on the inner surface of the cup. Each consists of a 

 swollen ovary at the base, containing one ovule, a long style, and 

 a slightly dilated stigma. The inner surface of the cup and the 

 surface of the ovaries are clothed with long silky hairs, and similar 

 but shorter hairs are borne on the style. The narrowing of the 

 mouth of the cup is due to the presence of a swollen yellow rim, 

 which has all the appearance of a nectary, though it secretes little 

 or no nectar. 



The flower is, however, visited by many insects (bees, beetles, 

 and flies), which come to collect or feed off the pollen. The 

 stamens and stigmas are mature at the same time, so that self- 

 or cross-pollination may result from the visits of the insects. 

 Since, however, the centre of the flower, where the group of stigmas 



