1954 



8. 



A TEXTBOOK OF THEORETICAL BOTANY 



dineae in which they are absent. Many species are cuhivated 

 and some are of economic importance. Anthemis nohilis is the 

 source of Chamomile, Artemisia and Tanacetiim are used as 

 herbs. Species of Chrysanthemum occur wild in Britain; C. 

 leiicanthemum is the Oxeye Daisy, C. segetum is the Corn Mari- 

 gold while C parthenium is Feverfew. C. indicum and C. sinense 

 which are native of China and Japan are the parents of the 

 cultivated Chrysanthemums. 

 Seuecioneae. Capitula homogamous or heterogamous. Involucral 

 bracts united into a cup with additional outer scales. Anthers 

 usually rounded at the base, filaments basifixed. Style with long 

 hairs below the fork. Pappus hairy. Receptacle generally without 

 floral bracts. Tussilago, Senecio, Petasites, Arnica, Doronicum 

 and Cineraria. 



Fig. 1885. — Senecio jdcobneti. Ragwort. 



The plants may be herbs, shrubs or trees with alternate leaves, 

 occurringmostlyin the Old World. The genus -S'^;/mo(Fig. 1885) 

 is by far the largest, with over 2,500 species, exhibiting almost 

 every type of habit. Several species, as already mentioned, 

 occur in Britain. Tiissilago farfara is the Coltsfoot while Petasites 

 fragrans (Winter Heliotrope) and P. officinah's (Butterburr) also 

 occur in Britain. All three spread rapidly by rhizomes. Coltsfoot 

 leaves are used as a substitute for tobacco. S. cruenta is the 



