i 3 6 FLOWERS OF THE ROADSIDES AND HEDGES 



menced to produce fruit, the aspect is rather like that of a candelabra, 

 and by this time the basal rosette of leaves has usually disappeared. 

 The plant is frequently covered with dust, more so than most wayside 



plants. 



It may be distinguished by its small yellow terminal racemes of 

 flowers borne on leafless branches. The pods are closely united to the 

 stem throughout their length, long, acute above, with sharp style, and 



borne on short flower-stalks, 

 being usually downy. The 

 leaves have a terminal 

 pointed lobe, and lateral ones 

 with the points turned back. 

 The Hedge Mustard is often 

 2 ft. high. It flowers from 

 May to July. It is annual, 

 and reproduced by seed. 



The flowers are similar 

 to those of Alliaria. On each 

 side of the 2 shorter stamens 

 are honey-glands, and each 

 of the 4 honey drops lies 

 between the stamens and 

 the pistil. The anthers and 

 stigma ripen together, and 

 the former face the latter. 



The longer anthers are 

 at first taller than the stigma, 

 and project when the flower 

 opens and bend inwards; the shorter ones, at first within the flower, 

 being ultimately on the same level, but not quite so long as the stigma, 

 curve outwards slightly. They all six grow, and the longer ones 

 exceed the stigma. Cross-pollination is arranged for, but may not 

 occur. In the absence of insects pollen from the four long stamens 

 falls on the stigma. The flowers are inconspicuous and visits are in- 

 frequent, but honey is sought by Pieris napi, P. rapce, which thrust 

 the proboscis between the stigma and anthers. Pollen is sought by 

 Andrena dorsata. The insects visiting it are Hymenoptera (Apiclae, 

 Andrena dor said}, Lepidoptera, as above. 



Hedge Mustard is dispersed by its own agency. The pods open 

 and allow the seeds to fall out around the plant, or disperse them to 

 some distance. 



HEDGE MUSTARD (Sisymbrium officinale, Scop.) 



