vi.] EXPLANA TION OF FORMS OF LEA VES. 145 



them the general habit is also, as a rule, more or less 

 similar. Is this the case in genera where the various 

 species differ greatly in habit ? I have already 

 incidentally given cases which show that this is not 

 so, but let us take some group for instance, the 

 genus Senecio, to which the common Groundsel 

 (Fig. 82) belongs, as a type well known to all of us 

 and look at it a little more closely. 



The leaves of the common Groundsel I need not 

 describe, because they are familiar to us all. This 

 type occurs in various other species of more or less 

 similar habit. On the other hand, the fen Senecio 

 (S. paludosus] and the marsh Senecio (S. pahistris], 

 which live in marshy and wet places, have long, narrow, 

 sword-shaped leaves, like those of so many other 

 plants which are found in such localities. The field 

 Senecio (S. campestris. Fig. 95), which lives in mea- 

 dows and pastures, has a small terminal head of 

 flowers springing from a rosette of leaves much like 

 those of a common Daisy (Bellis perennis] ; a 

 Madagascar species, as yet I believe unnamed, is 

 even more like a Daisy. Senecio junceus looks much 

 like a Rush ; 5. hypocharideus of South Africa 

 strikingly resembles a Hypochaeris, as its name denotes. 

 A considerable number of species attain to a larger 

 size and become woody, so as to form regular bushes ; 

 S. biixifolhis has very much the generaUlook of a 

 Box, 6". vagans of a Privet, .S. laurifolius of a Laurel, 

 eric&folius of a \\z?A.\\, pinifolius of a Fir, or rather, 

 a Yew. 



Again, some species are climbers ; 5. scandens 

 and >S. macroglossus have leaves like a Bryony ; 



L 



