OAKS. 215 



news 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 40 

 feet high at the home of Mr. J. S. Harris. In the forest plant- 

 ation at the Minnesota Experiment Station the young trees 

 are doing very well. 



The wood is used in the manufacture of cheap furniture, 

 for interior iinishing of houses, for railway lies, fence posts 

 and rails. Its durabilitv is due to the large amount of tan- 

 nic acid which it contains. An extract of the wood is largely 

 used in tanning. 



Oak Family. 



Genus QUERCUS. 



A very large genus of about 200 species which are not 

 always clearly defined. The four here described are nearly 

 distinct, but there are great variations in the species and 

 many undoubted hybrids. Flowers greenish or yellowish, 

 monoecious: the staminate in slender naked catkins, each 

 flower consisting of a 4 to 7-parted or lobed calyx and 4 to 

 12 stamens: the pistillate flowers scattered or somewhat clus- 

 tered, each consisting of a nearly 3-celled, 6-ovuled, inferior 

 ovary with a 3-lobed stigma and enclosed by a scaly bud-like 

 involucre which becomes the hardened cup (cupule) around 

 the base of the fruit, which is a rounded 1-celled nut or acorn. 

 Cotyledons remain underground in germination. 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 maturing the first year, inner surface of shell 

 glabrous; wood hard, close grained, durable; tree with deep 

 permanent tap root. 



