68 CHINESE ECONOMIC TREES 



India, Java and Southern China. 



From the material I have seen, I believe E. acerifolia Blume and 

 E. colebrook'ana Lindley belong here. The lntter is characterized by 

 dense tomentum on the under surface of the leaves. 



EngTehardtia chrysolepis Hance. 

 (E. wallicliiana Lindley.) 



Leaflets leathery, entire, quite glabrous. Staminate flowers with 

 lobed bracts and usually 12 stamens. Pistillate flower with a 4-lobe<l 

 stigma. Nutlet globose, 4 mm. in diameter, crowned with a 4-lobed 

 perianth covered with yellow, glandular scales; middle lobe of the bract 

 about 4 cm. long. 



Singapore, Hongkong, Yunnan, Szechuan. 



BETULACEAE 



Trees or shrubs. Branchlets with conspicuous lenticels. Leaves 

 alternate, simple, usually doubly serrate, with stipules. Flowers monoe- 

 cious, in catkins. The staminate 1-3, in the axils of the leaves, with 2-4 

 parted calyx, or calyx wanting; stamens 2-20, the filaments distinct, 

 inserted on a receptacle; the pistillate with or without calyx; ovary 

 inferior, 2 celled; ovules solitary in each cell, pendulous. Nutlet usually 

 winged, 2 celled, 1 seeded; seeds exalbuminous. Nutlets borne in a 

 strobile (Belula, etc.) or as enlarged nutlets enclosed in an involucre 

 (Corylus) . 



Six genera and about 75 species in the Northern Hemisphere. This 

 is an important fnm'ly, several genera are in cultivation for ornament, 

 fruit or timber. Betula is an important inhabitant of the forests of the 

 temperate region, and its timber is a valuable article of commerce. 



KEY TO GENERA 



A. Staminate flower solitary in the axils of the scale, without calyx; 

 pistillate flower with calyx; nuts not winged, subtended or enclosed 

 by an involucre formed of the bracts and bractlets of the flower. 



I. Staminate flowers with 2 bractlets; pistillate flower 2-4. 

 capitate; nuts large, enclosed in a leafy involucre. . . .Corylus. 



