144 TREES OF THE NORTHERN UNITED STATES 
ceolate to oblong-lanceolate, serrate with deep teeth. Fruit round- 
ish-ovate, regularly separable only half-way, but friable at maturity. 
Nut small, white, subglobose, with a very thin shell and an ex- 
tremely bitter kernel. Large tree with 
orange-yellow winter buds, and firm, not 
sealy, bark. Wild throughout, and some- 
times cultivated. 
7. Carya oliveeférmis, Nutt. (PECAN- 
nut.) Leaflets 11 to 15, ovate-lanceolate, 
serrate ; lateral ones nearly sessile and 
decidedly curved. Fruit oblong, widest 
above the middle, with 4 distinct valves. 
Nut oblong, 144 in., nearer smooth than 
the other edible Hickory-nuts, the shell 
thin, but rather too hard to be broken 
by the fingers. The kernel is full, sweet, 
©. olivesformis, and good. A tall tree, 80 to 90 ft. high. 
Indiana and south; also cultivated, but not very successfully, as 
far north as New York City. 
ORDER XXXIX. CUPULIFERZ. (Oak Famty.) 
This order contains more species of trees and shrubs in 
temperate regions than any other, except the Conifers. 
The genus Quercus (Oak) alone contains about 20 species’ 
of trees in the region covered by this work. 
Genus 838. BETULA. 
Trees or shrubs with simple, alternate, mostly straight- 
veined, thin, usually serrate leaves. Flowers in catkins, 
opening in early spring, in most cases before the leaves. 
Fruit a leafy-scaled catkin or cone, hanging on till 
autumn. Twigs usually slender, the bark peeling off 
in thin, tough layers, and having peculiar horizontal 
marks. Many species have aromatic leaves and twigs. 
