288 TREES OF MINNESOTA. 
contact with the soil, reddish brown, with thin, light colored 
sapwood. Specific gravity 0.4504; weight of a cubic foot 28.07 
pounds. 
Uses.—Within and near its range the Chestnut is an im- 
portant and very fast-growing timber tree that readily renews 
itself from sprouts from the roots. As an ornamental tree it 
is highly esteemed wherever it is hardy. In this section it is 
not sufficiently hardy to warrant any extensive planting of it, 
but has held on well for twenty years in Houston county, where 
are found thrifty trees eight inches in diameter and forty feet 
high at the home of Mr. J. S. Harris. In the forest plantation 
at the Minnesota Experiment Station the young trees are doing 
very well. 
The wood is used in the manufacture of cheap furniture, 
school globes and object forms, tool handles, kegs, for interior 
finishing of houses, for railway ties, fence posts and rails. Its 
durability is due to the large amount of tannic acid which it 
contains. An extract of the wood is largely used in tanning. 
Genus QUERCUS. 
A very large genus of about 200 species, which are not 
always clearly defined. The four here described are nearly dis- 
tinct, but there are great variations in the species, and many 
undoubted hybrids. Flowers greenish or yellowish, monoeci- 
ous; the staminate in slender naked catkins, each flower con- 
sisting of a four to seven-parted or lobed calyx and four to 
twelve stamens; the pistillate flowers scattered or somewhat 
clustered, each consisting of a nearly three-celled, six-ovuled, 
inferior ovary with a three-lobed stigma and inclosed by a 
scaly bud-like involucre, which becomes the hardened .cup 
(cupule) around the base of the fruit, which is a rounded one- 
celled nut or acorn. Cotyledons remain underground in germ- 
ination. All our species flower in the spring and shed their 
acorns in the autumn of the same or following year. This 
genus is readily divided into the White Oak and the Black 
Oak classes. 
The White Oak class is characterized by leaves with rounded 
lobes, teeth that are never bristle pointed; edible acorns ma- 
turing the first year, inner surface of shell glabrous; wood 
hard, close grained, durable; tree with deep permanent tap root. 
