68 CHINESE ECONOMIC TEEES 



India, Java and Southern China. 



Fro^ the material I have seen, I believe E. acerijolia Blume and 

 E. colehrookiana Lindley belong here. The latter is characterized by 

 dense tomentuna on the under surface of the leaves. 



Englehardtiei chrysolepis Hance. 

 •(E. wallicbiana Lindley.) 



, Leaflets leathery, entire, quite gliibrous. Staminate flowers with 

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

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

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

 about 4 cm. long. 



Singapore, Hongliong, Yunnan, Szechuan. 



BETULACEAE 



, Trees or shrubs. Branchlets with conspicuous lentieels. 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 (Salyx wanting; stamens 2-20, the filaments distinct, 

 inserted on a receptacle; the pistillate with or without calj'x; ovary 

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

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

 strobile! (Betula, etc.) or as enlarged nutletsi enclosed in an involucre 

 {Oorylus) . 



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

 is an important family, 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 bracllets of the flower. 



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

 capitate; iiuts large, enclosed in a leafy involucre. . . .Corylu&, 



