210 



THE BOOK OF NATURE STUDY 



into lateral shoots, which bear a few leaves and end in inflor- 

 escences ; the lateral shoots may in turn branch and bear in- 

 florescences. 



The inflorescence consists of the main axis of the shoot bearing 

 laterally placed flowers. It continues to grow for a long time, 

 producing a succession of flowers, and in old plants buds may 

 still be found near the tip of an inflorescence that lower down 

 bears almost ripe fruits. Each flower corresponds to a lateral 

 branch, but, as is the rule in the group to which the Charlock and 



the Lady's Smock belong, the bracts 

 are wanting below the flowers. 



The flower has a well-marked 

 green stalk. There are four, pale 

 green sepals, which completely cover 

 in all the other parts in the bud. 

 The sepals are in two pairs, those 

 of the outer pair being flatter than 

 those of the inner pair. The two 

 pairs alternate, the sepals of the 

 outer pair standing front and back 

 in the middle line. The corolla is 

 composed of four petals inserted at 

 the same level on the receptacle of 

 the flower, and alternating with the 

 four sepals. Each petal consists of 

 a narrow, erect, flat, stalk-like part 

 of a greenish colour, which widens 

 out into the oval yellow upper portion. The four yellow 

 expansions are bent at right angles to their stalks, and diverge 

 in the form of a cross. Within the corolla, as is best seen on 

 removing the sepals and petals from a flower, are six stamens. 

 These stand at two levels on the receptacle. To either side of 

 the flower, and at the lower level on the receptacle, is a single 

 stamen which is shorter than the stamens of the inner whorl. 

 These are four in number, one pair standing to the front and the 

 other to the back in the flower as it stands on the main stem. 

 The filaments bear fairly large anthers which on opening liberate 

 yellow pollen. In the centre of the flower is the pistil. This is 



FIG: 94. Shoot of the Charlock 

 bearing flowers and fruits. (After 

 Baillon.) 



