SUPPLEMENT. 



THE FAMILIES OF FLOWERING PLANTS. 



By Chaeles Louis Pollard. 



CHAPTER HHl— 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- 

 gether with spiraea, cinque- 

 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. Ill 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 



Fig. no. Flowering branch and enlarged flower of 

 the southwestern desert shrub, Crossosoma Bigelovii. 

 Original. 



