224 



BOTANY. 



and elder (Sambucus) ; III. Valerianece, represented by the 

 common valerian ( Valeriana) (Fig. 124, L) ; IV. Dipsacece, 

 of which the teasel (Dipsacus) (Fig. 124, P), is the type, and 



also species of scabious 

 (Scabiosa) ; V. Com- 

 positce, to which the 

 innumerable, so-called 

 compound flowers, 

 asters, golden - rods, 

 daisies, sunflowers, etc. 

 belong; VI. Calycerece. 

 Besides the groups 

 already mentioned, 

 there are several fam- 

 ilies of dicotyledons 

 whose affinities are 

 very doubtful. They 

 are largely parasitic, 

 e.g. mistletoe ; or water 

 plants, as the horned 

 pond-weed (Cerato- 

 phyllum). One family, 

 the Aristolochiacece^ep- 

 resented by the curi- 

 (Aristolochia sipho), a woody twiner 



FIG. I26. Aristolochiacese. A, plant of wild 

 ginger (Asarum), x %. B, vertical sec- 

 tion of the flower, x I. C, diagram of the 

 flower. 



ous " Dutchman's pipe 



with very large leaves, and the common wild ginger (Asarum) 

 (Fig. 126), do not appear to be in any wise parasitic, but the 

 structure of their curious flowers differs widely from any other 

 group of plants. 



