Hill's Oak 



291 



8. HILL'S OAK Quercus ellipsoidalis E. J. Hill 



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. veluiina 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-halry, soon becoming nearly smooth, light reddish 

 browTi, 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 5 or 7 lobes are 

 oblong lo 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 primar}' 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 leaf- 

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



