FAMILIES OF FLOWERING PLANTS. 243 
almost entirely tropical group con- 
tains about 355 genera and 5500 
species of wide distribution. They 
are herbs, shrubs or trees, with a 4-5- 
lobed calyx and corolla of varying 
shape. The ovary is 1-10-celled, be- 
coming in fruit a capsule, berry or 
drupe. Rubiaceous plants may usu- 
ally be recognized by the stipules or 
leaf-like membranes uniting the 
bases of the opposite or whorled 
leaves. The family is of great 
economic importance, containing, as 
it does, beverage, dye and medicinal 
plants, not to mention those of orna- 
mental value. In the tribe Cincho- ee Se 
neae, for example, is found the genus northeast U. S. 
Cinchona, which consists of evergreen trees growing chiefly in the val- 
leysof the Andes of Peru. Several species yield what is known com- 
mercially as Peruvian bark, and it is from this that quinine and the 
related alkaloids are obtained. These barks have different properties 
according to the relative proportions of the alkaloid they contain ; but in 
all cases the extract is extremely bitter and possesses prominent tonic 
qualities. 
The same group contains Bouvardia, a genus of handsome green- 
Fic. 211, ‘The Partridge-berry (Mitchella repens). After Britton and 
Brown, Ill. Fl. Northeast U. S. 
house shrubs, one species of which (B. triphylla) is native in our south- 
