Hill's Oak 



291 



8. HILL'S OAK — Quercus ellipsoidalis E. J. HiU 



A tree of clay soils from northern Illinois and Michigan, westward to eastern 

 Iowa and southeastern Minnesota, apparently very local and related to the Black 

 oak, Q. velutina Lamarck, and the Scarlet oak, Q. coccinea Muenchausen, of which 

 it has been considered a hybrid. Its maximum height is 21 meters, with a trunk 

 diameter of 1.2 m. It is also called Yellow oak and Black oak. 



The branches are much divided, often drooping and usually long persistent on 

 the lower portion of the trunk, the tree oblong in outline. The bark is rather 

 thin, shallowly fissured into close narrow thin, dark brown plates, yellow internally; 

 on younger stems it is quite smooth, varying from gray to grayish brown. The twigs 



» Fig. 243. — Hill's Oak. 



are slender, at first appressed-hairy, soon becommg nearly smooth, light reddish 

 brown, finally dark gray or brown. The winter buds are ovoid, 6 mm. long, sharp 

 or blunt-pointed, slightly angular, reddish brown and shining. The leaves are 

 oval, obovate to nearly orbicular in outline, 6 to 15 cm. long; the S or 7 lobes are 

 oblong to triangular with bristle-pointed teeth; the sinuses are very deep, wide, 

 and rounded or obovate, the base is broadly wedge-shaped or blunt. They are 

 thin but firm in texture, bright green and shining above, with a prominent yel- 

 lowish rounded midrib and primary veins, paler, and smooth except for tufts 

 of hairs at the axils of the prominent venation beneath, turning yellowish or brown- 

 ish, often variegated with red and purple before falling in the autumn. The leafr 

 stalk is slender, grooved, and usually smooth, 2.5 to 5 cm. long. The flowers 



