CLASSIFICATION OF ANGIOSPERMS. 517 



(A. integri folia) of the East Indies, the WHITE MULBERRY (Morus 

 alba) and the BLACK MULBERRY (Morus nigra). 



The leaves of the white mulberry (Morus 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^E. The plants belonging to the 

 Urticacese 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 Urtica 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. spatulata of 

 Timor, Laportea crenulata of tropical Asia, L. moroides of 

 Queensland, and Girardinia palmata of India. In the small 

 nettle (Urtica urens) of Europe and the United States an alka- 

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

 fish poison. Boehmeria cor data 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. urens and Boehmeria nivea of 

 the Sunda Islands and China, the latter of which yields RAMIE. 

 The akene of Debregeasia edulis of Japan and the rhizome of 

 Pouzolzia tuberosa of China and Japan are edible. 



VII. ORDER PROTEALES. 



The members of this 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 Leucadendron argenteum and L. continuum, both 



