242 BRITISH FLOWERING PLANTS chap. 



G-NAPHALIUM 



Wind-flowers, with small flower-heads. Eay florets 

 female, filiform., in several rows. Disk flowers com- 

 plete, tubular. Achenes with a silky pappus. There 

 are four British species. The name of the genus recalls 

 the woolly habit of the plants. Edelweiss belongs to 

 a closely allied genus, Leontopodium. G. supinum is 

 typical in this respect (see p. 28). 



Senecio 



Eay flowers female, sometimes wanting ; disk flowers 

 complete. Achenes with silky pappus. We have eleven 

 species. The genus is very large, and widely distributed. 



S. vulgaris (Groundsel). — The florets are almost 

 always all tubular ; there are 60-80 in a head. The 

 honey is abundant, but from the smallness of the 

 flower-heads insect visits are not numerous. Bateson 

 has experimented with this species, and found that 

 seeds which were the result of cross -fertilisation pro- 

 duced more vigorous plants than those resulting from 

 self- fertilisation. The plant is annual with us, but 

 becomes perennial in Alpine districts (see Cardamine 

 hirsuta, p. 79). It is glabrous, or with a little 

 cottony wool. The sides of the achenes have short 

 appressed hairs, as also have those of S. sylvaticus. 

 These hairs secrete a mucus, which serves to attach 

 the achenes to damp soil. 



S. viscosus. — This is one of the species in which the 

 access of creeping insects is precluded by the presence 

 of a sticky secretion. The plant is covered with a short, 

 viscous, unpleasantly smelling down. The achenes are 

 glabrous. 



S. Jacobsea (Ragwort). — This species is perennial. 

 It has an unpleasant odour. The flower-heads are large, 

 showy, and much visited by insects. The plant is 

 glabrous, or with a loose woolly down. The achenes of 

 the disk have short hairs, those of the ray are glabrous. 

 This is also the case with those of S. aquaticus. 



