152 FAMILIES OF FLOWERING PLANTS 
are herbs or shrubs, in some regions leafless and fleshy, like cacti, 
which they replace in the deserts of the Old World. Our species are 
mostly herbs of weedy aspect. They frequently have the upper leaves 
and bracts brilliantly colored, as in the familiar poinsettia, which is a 
Euphorbia. E. marginata, represented in Fig. 131, belongs to this 
class. 
Fig. 131. The white-margined spurge (Euphorbia marginata). Original. 
The milky juice which is found in members of this genus possesses 
important medicinal properties. It is also very poisonous when taken 
internally, though the poisonous principle may be dissipated by the 
action of heat. A fair article of caoutchouc is made from the juice of 
an East Indian species. 
Family Callitrichaceae. Water Starwort Family. These are 
