CLASSIFICATION OF DICOTYLEDONS. 



203 



the inflorescence are perfect. In the garden varieties, all of 

 the flowers are changed, by selection, into the showy, neutral 

 ones. The syringa or mock orange (Philadelphus) (Fig. Ill, 

 7), the gooseberry, and currants (Eibes) (Fig. Ill, A), and 

 the stonecrop (Sedum) (Fig. Ill, E) are types of the families 

 Philadelphece, Hibesiece, and Crassulacece. 



FIG. 111. Calyciflorse (Saxifraginse) : A, flowers and leaves of wild goose- 

 berry, Ribes (Ribesiess), x 1. B, vertical section of the flower, x 2. (7, 

 diagram of the flower. D, flower of bishop's-cap, Mitella (tiaxifrayacese) , 

 x 3. E, flower of stonecrop, Sedum (Crassulacese), x 2. F, flowers and 

 leaves of hydrangea (Hydrangeae) , x %. n, neutral flower. G, unopened 

 flower, x 2. H, the same, after the petals have fallen away. I, flower of 

 syringa, Philadelphus (Philadelphese) , x 1. J, diagram of the flower. 



The third order (Opuntiece) has but a single family, the 

 cacti (Cactacece). These are strictly American in their distri- 

 bution, and inhabit especially the dry plains of the southwest, 

 where they reach an extraordinary development. They are 

 nearly or quite leafless, and the fleshy, cylindrical, or flattened 

 stems are usually beset with stout spines. The flowers (Fig. 



