CLASSIFICATION OF AXGIOSFERMS. 517 



(A. intcgrifolia) of the East Indies, the white mulberry {Monis 

 alba) and the black mulberry {Mortis nigra). 



The leaves of the white mulberry {Morns alba), indigenous 

 to China and cultivated since the twelfth century in Europe and 

 now in cultivation to a limited extent in the United States, are 

 the chief food of the silkworm. 



c. FAMILY URTICACE^.— The plants belonging to tlie 

 Urticaceae or Nettle family are chiefly herbs with mostly petiolate, 

 stipulate, simple leaves. The flowers are small and with 2 to 5 

 distinct or more or less united sepals. The fruit is an achene ; 

 the embryo is straight and surrounded by an oily endosperm. The 

 stems and leaves of several of the genera are characterized by 

 stinging hairs, this being .especially true of the sub-group to which 

 the genus L>tica or stinging nettle belongs. Of the stinging 

 nettles the following are used in medicine: Urtica dioica of 

 Europe and naturalized in the United States, U. spatidata of 

 Timor, Laportca crenulata of tropical Asia, L. moroidcs of 

 Queensland, and Girardinia palmata of India. In the small 

 nettle {Urtica iirens) of Europe and the United States an alka- 

 loid has been found, and Laportea stimidans has been used as a 

 fish poison. Bochmeria cordata of Brazil is used as a substitute 

 for Arnica. The fibers of a number of the Urticacese have been 

 found useful, of which the following may be mentioned : Urtica 

 cannabina of Asia, U. dioica, U, urcns and Boehmeria nivea of 

 the Sunda Islands and China, the latter of which yields Ramie, 

 The akene of Dcbrcgeasia edulis of Japan and the rhizome of 

 Pouzohia tubcrosa of China and Japan are edible. 



VII. ORDER PROTEALES. 



The members of tiiis group are mostly shrubs and found prin- 

 cipally in the Tropics and southern hemisphere, several species 

 being cultivated in greenhouses for the sake of the beautifully 

 colored flowers which are in crowded inflorescences. The order 

 is represented by but a single family, namely, the Proteacese. 

 The leaves are leathery and vary even on the same plant from sim- 

 ple to compound. The glucoside proteacin and a bitter principle 

 are found in Leucadcndron argentcum and L. concinuHui, both 



