DIV. n 



ANGIOSPERMAE 



625 



persists on the other hand in the seed ; the separation of the latter from the 

 placenta is assisted by it. The fruit is a capsule, the outer walls of which contract 

 elastically away from* a central column, and thus open the loculi. 



The plants of this family are distributed over the whole earth, IMPORTANT 

 GENERA. Many Euphorbiaceae are dioecious or monoecious, and have flowers of 

 relatively simple construction. Thus Mecwialis (Fig. 622), two species of which 





Fi<;. 020. Ricinus communis, greatly reduced. (After BAILLOX.) Porsoxocs and OFFICIAL. 



occur in Britain, is characterised by its bicarpellary ovary. Croton is a tropical 

 genus including valuable official plants, C. Eleuteria and C. Tiylium ; the male 

 flowers have a double, the female flowers a single perianth. In the Spurges 

 (Euphorbia"), of which there are several British species, a number of the extremely 

 simply constructed flowers are grouped in a complicated inflorescence termed a 

 CTATHIUM (Figs. 623-625). This consists of a naked, terminal, female flower, 

 borne on a long bent stalk surrounded by a number of groups of male flowers. 

 Each of the latter is stalked and consists of a single stamen, the limit between 

 which and the flower-stalk is distinguishable. In some cases the female flower 



2S 



