234 FAMILIES OF FLOWERING PLANTS 
Fic. 203. Jimson-weed (Datura Stramonium): a. flower and leaf; b, fruit; 
both one-third natural sizes. (After Chesnut, Bull. No. 20, Div. of 
Bot. U. S. Dep't of Agric.) 
certainly a troublesome weed, it is not altogether without its uses, as the 
leaves enter into nearly all preparations for the cure of asthma. 
Not the least important member of the family is the genus Nicotiana, 
the tobacco. There are a number of wild species, but the tobacco of 
commerce is chiefly derived from N. Tabacum. 
