49 



THE POPULAR SCIENCE MONTHLY. 



the ease 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. 24) 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. palus- 

 tris), 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. cam- 

 pestris, Fig. 34), which lives in meadows and 

 pastures, has a small terminal head of flowers 

 springing from a rosette of leaves much like 

 those of a common daisy (JSellis perennis) ; 



a Madagascar species, as yet I believe un- 

 named, is even more like a daisy. Senecio 

 junceus looks much like a rush ; S. hypo- 

 chcerideus, of South Africa, strikingly resem- 

 bles a hypochceris, as its name denotes. A 

 considerable number of species attain to a 

 larger size and become woody so as to form 

 regular bushes. S. buxifolius has very much 

 the general look of a box, S. vagans of a privet, S. laurifolius of a 

 laurel, ericcefolius of a heath, pinifolius of a fir, or rather a yew. 



Again, some species are climbers : S. scandens and S. macroglossus 

 have leaves like a bryony ; S. araneosus and S. tamoides like a smilax 

 or (yam) tamus ; S. tropceoUfolius like a tropseolum. 



Among the species inhabiting hot, dry regions are some with swol- 

 len, fleshy leaves, such as S. haworthii, from the Cape of Good Hope, 

 and S. pteroneura, from Magador. Senecio rosmarinifolius, of the 

 Cape, is curiously like a rosemary or lavender. 



Lastly, some species may almost be called small trees, such as S. 

 popidifolius, w r ith leaves like a poplar ; and S. amygdaloides, like an 

 almond. 



I might mention, if space permitted, many other species which, as 

 their names denote, closely resemble forms belonging to other groups 

 such, for instance, as Senecio lobelioides, erysimoides, bupleurioides, 

 verbascifolius, juniperinus, ilicifolius, acanthifolius, linifolius, platani- 

 folius, graminifolius, verbenefolius, rosmarinifolius, coronopifolius, 

 chenopodifolius, lavanderisefolius, salicifolius, mesembryanthemoidee, 

 digitalifolius, abietinus, arbutifolius, malvsefolius, erodiifolius, halimi- 

 folius, hakesefolius, resedsefolius, hedertefolius, acerifolius, plantigineus, 

 castaniaefolius, spiroeifolius, bryonioefolius, primulifolius, and many 



