SUPPLEMENT. 
THE FAMILIES OF FLOWERING PLANTS. 
By Cuarzes Lovis Potwarp. 
CHAPTER XXI—Continued. 
Family Crossosomataceae. Crossosoma Family. Consists of the 
genus Crossosoma, with two species, natives of our southwestern bor- 
der, extending into Mexico. They are shrubs with small coriaceous 
leaves and white flowers with a superior ovary composed of a number 
of separate carpels (see Fig.110). The genus is an anomalous one, and 
has been placed by some bot- 
anists in the Ranunculaceae, 
by others in the Dilleniaceae, 
but it is best regarded as the 
type of a distinct group. 
Family Rosaceae. Rose 
Family. The modern tendency 
toward the recognition of 
smaller and more sharply de- 
fined natural families of plants 
is well exemplified in the 
Rosaceae as they now appear 
in our text-books. The old 
family included pears, plums, 
apples and their allies, to- Fig. 110. Flowering branch and enlarged flower of 
gether with spiraea, cinque- a or desert shrub, Crossosoma Bigelovii. 
foil, blackberry and straw- 
berry. The apples and pears are now separated as the family Poma- 
ceae, while the plums, cherries, etc., constitute the family Drupaceae. 
The Rosaceae proper, containing all other genera of the group, are 
characterized by the regular flowers with 5 sepals, 5 petals, numerous 
stamens, and 1 to many carpels, distinct or united to the calyx. The 
fruit is usually an achene; the plants themselves are herbs, shrubs, or 
rarely trees. There are 65 genera and over 1200 species, of very wide 
geographic distribution. In Fig. 111 the two uppermost flowers exhibit 
two distinct types of structure found in this family: the hypogynous 
flower, in which the stamens are borne on the receptacle beneath the 
