CLASSIFICATION OF ANGIOSPERMS. 697 



VI. ORDER RUBIALES. 



The plants of this order are distinguished from all of the 

 preceding Sympetalae by having flowers which are distinctly epigy- 

 nous. The leaves are opposite or verticillate. 



a. RUBIACE^ OR MADDER FAMILY. The plants are 

 herbs, shrubs, or trees, and of the representatives found in the 

 United States the following may be mentioned: Bluets (Hous- 



PIG. 386. Cinchona Ledgeriana: A, flowering branch; B, bud and open flower; 

 C, fruiting branch. After Schumann. 



tonia species), Partridge-berry (Mitchella re pens), and Bedstraw 

 (Galium species). In Mitchella and Houstonia the flowers are 

 dimorphic. 



CINCHONA species. The plants are mostly trees, or rarely 

 shrubs, with elliptical or lanceolate, entire, evergreen, petiolate, 

 opposite leaves (Fig. 386). The flowers are tubular, rose-colored 

 or yellowish-white, and occur in terminal racemes. The fruit is 

 a capsule, which dehisces into two valves from below upward, 

 the valves being held above by the persistent calyx. The seeds 



