INTRODUCTION xxxiii 



Rhizophorace^. — Rhizophora is common on the shores of 

 tropical Florida, but the family is more largely represented in 

 tropical China by Kandalia, Bruguiera, and Carallia. 



CoMBRETACE^. — Represented in tropical Florida by Bucida, 

 Conocarpus, and Laguncularia, this family appears in China in 

 Combretum, Quisqualis, and lUigera. 



Myrtace.e. — Rhodomyrtus, Eugenia, Psidium, and Baeckea 

 of the Myrtle family have reached south-eastern China, while in 

 tropical Florida occur Eugenia, Anamomis, Chytraculia, and 

 Syzygium. 



Melastomace^. — Of this family woody species of Barthea, 

 Allomorphia, Blastus, Bredia, Anplectrum, and Memecylon occur in 

 China, but a species of Tetrazygia is the only woody member of 

 the family in eastern North America. 



Araliace^. — An arborescent species of Aralia and a species of 

 Echinopanax are the only tree and shrub of this family in eastern 

 North America ; in eastern continental Asia the family is more 

 largely represented by Aralia, Acanthopanax, Fatsia, Nothopanax, 

 Heptapleurum, Dendropanax, Heteropanax, and Hedera. 



CornacE/E. — Of this family Garrya occurs in eastern North 

 America but not in China, where are found the monotypic Campto- 

 theca, a large tree, Davidia, Alangium, Helwingia, Torricellia, 

 Marlea, and Aucuba. Nyssa and Cornus are common to the two 

 regions. Nyssa in America is widely and generally distributed from 

 New England to Florida and Texas, with several species, of which 

 two are large trees, but in China only a small tree is now known, 

 confined to the central provinces. On the other hand, Cornus is 

 more numerous in species in China than in eastern North America, 

 six of the species at least being arborescent and one a tree occasion- 

 ally 100 ft. high. 



Clethrace^. — Of this family there are three species of Clethra 

 in each of our two regions. 



Ericace.e. — In the number of genera of this family eastern 

 North America has the advantage of the Asiatic region, with twenty- 

 three genera in the former and only seventeen in the latter. Such 

 genera as Bejaria, Leiophyllum, Menziesia, Kalmia, Zenobia, 

 the monotypic Oxydendrum, Gaylussacia, and Arctostaphylos have 

 no eastern Asiatic representatives. Enkianthus, Craibiodendron, 

 and Diplycosia are Chinese, without American representatives, 

 and the following genera are common to the two regions : Vaccin- 

 ium, Gaultheria, Chamgedaphne, Loiseleuria, Phyllodoce, Andromeda, 

 Arctous, and Rhododendron. No single genus except Crataegus so 



