XXX A NATURALIST IN WESTERN CHINA 



and Mortonia are American. Only one species of Celastrus and 

 three species of Evonymus occur in eastern North America, but in 

 eastern continental Asia the species of these genera are much more 

 numerous, and the species of Evonymus are usually larger and more 

 beautiful plants. 



HiPPOCRATEACEiE. — Of this Small tropical family there is a 

 species of Hippocratea in tropical Florida and two or three in 

 southern China. 



Staphyleace^. — Represented in China by Staphylea, Turpinia, 

 Euscaphis, and Tapiscia, this family is much more important in 

 eastern continental Asia than in eastern North America, where there 

 is a single species only of Staphylea. 



Icacinace^. — Without an eastern North American genus this 

 family appears in China in lodes, Mappia, and the monotypic 

 Hosiea. 



Acerace^. — Eastern continental Asia with its sixty-four 

 species is far richer in Acer than eastern North America, where only 

 ten species occur. The American Maples, however, are more 

 widely distributed, and are larger and more valuable timber trees ; 

 Dipteronia and Dodongea of this family are Chinese. 



HiPPOCASTANACE^. — Of this family, ^sculus appears in two 

 arborescent species in China, one in the north and one on the 

 mountains of the west, but in eastern North America, where more 

 species are segregated than in any other part of the world, four 

 arborescent and four shrubby species occur in the southern United 

 States. The monotypic Bretschneidera is Chinese. 



Sapindace^. — Of the woody plants of this family found in our 

 two regions, Urvillea, Serjania, Exothea, Hypelate, Cupania, and 

 the monotj^Dic Ungnadia are American, and the monotypic genera 

 Xanthoceras and Delavaya, with Nephelium, Schmidelia, Koelreu- 

 teria, and Pancovia, are Chinese ; Sapindus is common to the two 

 regions. 



Sabiace^, — Without representatives in eastern North America, 

 this family appears in China in Sabia and Meliosma. 



Rhamnace^. — Of this family, several genera reach tropical 

 Florida from the West Indies and the dry region of Texas from 

 Mexico, and the number is larger in eastern North America than in 

 eastern continental Asia. The exclusively American genera are 

 Rhamnidium, Reynosia, Ceanothus, Condalia, Karwinskia, Colu- 

 brina, and Gouania ; and the Asiatic genera are Ventilago, Paliurus, 

 and the monotypic Hovenia. Sageretia, Zizyphus, Berchemia, and 

 Rhamnus have representatives in the two floras. Species of 



