122 



THE BOOK OF NATURE STUDY 



axis, which does not end in a flower, is unlimited, may be contrasted 

 with that of the Buttercup or Lesser Celandine (cf. Fig. 52). 



Each flower consists of a flower-stalk bearing, in order from 

 below upwards, the calyx, corolla, stamens, and pistil, which are 

 crowded together on the end of the stalk or the floral receptacle. 

 In the bud only the calyx, the sepals of which completely cover 

 in and protect the other parts of the flower, is visible. The four 

 sepals do not stand at the same level on the receptacle, but are 

 arranged in two pairs. The sepals of one pair, those standing 



front and back in the flower, are 

 narrower than those of the other 

 pair, and the latter are also bulged 

 out at the base. A little careful 

 observation is needed to make out 

 which pair is outermost, but if it is 

 noticed which pair overlaps the 

 other it will be clear that the 

 narrower sepals are the lower ones, 

 although the bulging downwards of 

 the bases of the other pair suggests 

 at first glance an opposite interpreta- 

 tion. The corolla is composed of four 

 showing the six stamens around pe tals, which, unlike the sepals, all 



the pistil and the nectaries at the j ,, i i ' T i_ 



bases of the two short stamens. stand at the Same leveL Each P etal 



stands above the interspace between 

 two sepals. As will be seen if the 

 sepals are removed from a flower, the 

 petals are all quite distinct or free 

 from one another. Each consists of an erect stalk-like portion 

 of a greenish-yellow colour, and of a wider oval portion which 

 is bent so as to stand almost at right angles to the lower part. 

 The end portions are coloured lilac, the colour being more 

 strongly marked in the veins, and the four petals diverge like 

 the arms of a cross, forming the most conspicuous part of the 

 flower. The lower portions of the petals are enclosed and held 

 together by the erect sepals, so that a sort of tube which 

 surrounds the other parts of the flower is formed by -the calyx 

 and corolla. 



A B 



FIG. 62. Lady's Smock. A, flower 

 with sepals and petals removed, 



B, the same cut in half to show 

 the construction of the ovary 

 and the position of the ovules. 

 (After Baillon.) 



