486 



ANGIOSPERMS 



Spurge Family (Euphorbiaceae) . -- The Spurge family con- 

 tains many species, many of which are tropical. The flowers 

 are commonly small, hypogynous, and unisexual. The perianth 

 is usually simple and sometimes absent. The stamens range 

 from one to many, and the pistil is composed of three united 

 carpels (Fig. 4^3). The plants usually contain a milky juice, 

 which in many species is poisonous. A few of them are common 

 weeds, usually growing prostrate in gardens and truck patches. 



FIG. 433. Flowers and fruit of the Flowering 

 Spurge (Euphorbia corollatd). At the right, a por- 

 tion of a plant in flower; above, at the left, a 

 flower cluster consisting of one pistillate flower and 

 a number of staminate flowers enclosed by an in- 

 volucre (i) bearing appendages resembling petals; 

 at the right of the flower cluster, a single stami- 

 nate flower with anther at a; below, at the left, 

 a flower cluster with staminate flowers removed 

 to show the pistillate flower; below, at the right, a 

 pistillate flower in fruit, showing the ovary (c), the 

 stigma (s), and the involucre (i}. In part after 

 Bergen and Caldwell. 



FIG. 434. The Hevea 

 tree, one of the plants 

 from the milk- juice of 

 which India rubber is ob- 

 tained. After Lecomte. 



The Castor Bean, from which castor oil is obtained, is one of the 

 large species of our region. Some are trees, as for example the 

 Hevea tree (Fig. 4$4) of South America from which India rubber 

 is obtained. Tapioca is obtained from the Cassava plant, a 

 plant of the Spurge family and native of Brazil. A number are 

 useful for medicine, and some, as the Castor Bean, Poinsetta, 

 and some others, are ornamental plants. 



Between the Pea family and the Spurge family is usually 

 placed the Flax family (Linaceae) to which the cultivated Flax 



