CLASSIFICATION OF DICOTYLEDONS. 



219 



centauries (Erythercea and Sabbatia), and several other less 

 familiar genera ; Loganiacece, with the pink-root (Spigelia) 

 (Fig. 122, D), as the best-known example ; Apocynacece, includ- 

 ing the dog-bane (Apocynum) (Fig. 122, H), and in the gardens 

 the oleander and periwinkle ( Vinca) . 



FIG. 122. Anisocarpous sympetalse (Contortse). A, flower of fringe-tree, 

 Chionanthus (Oleacese), x 1. B, base of the flower, with part of the calyx 

 and corolla removed, x 2. C, fruit of white ash, Fraxinus (Oleacese), x 1. 

 D, flower of pink-root, Spigelia (Loyaniacese) , x y 2 . E, cross-section of the 

 ovary, x 3. F, flower of fringed gentian, Gentiana (Gentianacese) , x y 2 . 

 G, diagram of the flower. H, flowering branch of dog-bane, Apocynum 

 (Apocynacese) , x %. J, vertical section of a flower, x 2. J, bud. Jf, flower 

 of milk-weed, Asclepias (Asclepiadacese), x 1. L, vertical section through 

 the upper part of the flower, x 2. yy. pistil, p, pollen masses, an. stamen. 

 M, a pair of pollen masses, x 6. N, a nearly ripe seed, x 1. 



The last family is the milk-weeds (Asdepiadacece) , which 

 have extremely complicated flowers. Our numerous milk- 

 weeds (Fig. 122, K) are familiar representatives, and exhibit 

 perfectly the peculiarities of the family. Like the dog-banes, 

 the plants contain a milky juice which is often poisonous. 



