SINO-MONGOLIAN FRONTIER 
(6) ANGIOSPERMS 
Turning from the gymnosperms we find a great 
number of trees, comparatively few of which, 
however, are good wood-producers. In the moun- 
tamous regions of Shansi and Kansu, and over 
the loess hills of Shensi, where uncultivated areas 
occur, we find such small trees as the Hazel, the 
Birch, a small variety of Poplar and a stunted 
Oak growing in great profusion, and forming 
dense coverts for various kinds of game. 
There are several species of Hazel (Corylus), 
one of which (Corylus heterophylla) is a tall, spare 
tree, scarcely more than a shrub, with small leaves 
and a very meagre crop of small nuts. This 
plant grows as a small tree in sheltered spaces in 
the heavy timber of Larch and Spruce, or as a thick 
shrub in dense patches on the more exposed slopes. 
Another species (C. mandshurica) is a large-leafed 
shrub, which produces a large nut, sometimes in 
great profusion. This variety is far less common 
than the other. 
The Birch (Betula sp.), usually occurring at 
fairly high altitudes, reaches a greater size than 
the largest Hazel. Its bark readily peels, and is 
used by the natives in the manufacture of utensils 
and mats. In the high mountains of Shansi it is 
particularly abundant. In North Chihli and 
North Shansi it is often the only tree growing in 
sparse woods on the northern slopes of the moun- 
tains. The trunk seldom reaches a greater dia- 
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