xxvi A NATURALIST IN WESTERN CHINA 



PiTTOSPORACE^. — Pittosporum, which reaches southern and 

 Western China with a few species, is the only genus of this family 

 in the two regions. 



HAMAMELIDACE.E. — This family is more important in the number 

 of genera in eastern continental Asia than in eastern North America, 

 where there is one endemic genus, Fothergilla. Hamamelis and 

 Liquidambar occur in the two regions, and in China the family is 

 represented also by Distylium, Corylopsis, Fortunearia, Sinowilsonia, 

 Loropetalum, Sycopsis, Eustigma, Rhodoleia, and Altingia. In each 

 region the Liquidambar is a large, widely distributed, and valuable 

 timber tree. The Chinese Hamamelis, like one of the American 

 species and the species from Japan, flowers in the winter. 



Platanace^. — Platanus, the only genus of the family, which is 

 represented in eastern North America by a large, common, and widely 

 distributed tree, has not reached eastern Asia. 



RosACEiE. — Of the thirty-four genera of the woody plants of 

 this family found in the two regions, Neillia, Stephanandra, Sorbaria, 

 Sibiraea, Exochorda, Cotoneaster, Osteomeles, Chsenomeles, Docynia, 

 Pyrus, Eriolobus, Pyracantha, Rhaphiolepis, Eriobotrya, Photinia, 

 Stranvsesia, Rhodotypos, Kerria, Prinsepia, Pygaeum, and Maddenia 

 occur in China only. Three genera, Aronia, the monotypic Neviusia, 

 and Chrysobalanus are American and not Chinese ; and ten genera 

 are common in the two regions, Physocarpus, Spiraea, Rosa, Malus, 

 Sorbus, Amelanchier, Crataegus, Rubus, Potentilla, and Prunus. Of 

 the genera common to the two regions, Physocarpus, with one species 

 in eastern Siberia, is better represented in eastern North America, 

 where the genus is widely distributed with several species. On the 

 other hand, the closely related Spiraea has a few small eastern 

 American species, but abounds in China, which is the centre of 

 greatest distribution of this genus. Eastern continental Asia, too, 

 is greatly superior to eastern North America in species of Rosa, and 

 in their variety and horticultural value, for China is the home of 

 Rosa IcBvigata Michx., Rosa hracteata Wendl., Rosa BanksicB R. Br., 

 Rosa muUiflora Thunb., Rosa indica L., the origin of the Tea Roses 

 of gardens, and of Rosa rugosa Thunb. The number of species of 

 Malus is probably about the same in the two regions, but it is inter- 

 esting that those of eastern North America all belong to a group 

 (Coronariae) which is not represented in eastern Asia, where the 

 small-fruited species with a deciduous calyx predominate. Sorbus 

 in eastern North America is represented by two species of the 

 Aucuparia section, while in eastern Asia there are nearly thirty 

 species in this group and at least ten species of Aria which does not 



