California Rock Oak 



323 



side, thin and embracing about one fourth of the nut, covered by thin, ovate, 

 imbricated hairy scales not corky-thickened on the back. 

 The wood is hard, close-grained and hght brown. 



41. CALIFORNIA ROCK OAK — Qnercus Douglasii Hooker and Amott 



A tree of dry hills and moimtain sides of west central California, southward to 

 Kern county, attaining a maximum height of 36 meters, with a trunk diameter of 

 1.2 meters, but often reduced to a shrub in its southern range. 



The branches are short and stout, the lower widely spreading, the tree usually 

 round-topped and broad. The bark is up to 2.5 cm. thick, pale gray or nearly 

 white, and somewhat scaly. The twigs are stout, very brittle, softly woolly during 

 the first season, becoming less hairy, gray or brown, finally smooth. The winter 

 buds are ovoid, blunt, 3 to 6 mm. long, reddish and hairy. The leaves are very 

 variable, oblong, oval or obovate, 

 5 to 12.5 cm. long, pointed or 

 rounded at the apex, narrowly or 

 broadly rounded, or heart-shaped 

 at the base; the 4 to 7 lobes are 

 broad or narrow, sharp-pointed, 

 bristle-tipped or rounded, the sin- 

 uses deep or shallow, acute or 

 rounded at the bottom; they are 

 sometimes entire except for a few 

 teeth toward the apex, thin, but 

 firm and stiff, bluish green with 

 scattered hairs and raised rounded 

 midrib above, paler or yellowish 

 green, softly hairy and more or less 

 conspicuously reticulate veined be- 

 neath. Tl^y fall in the late au- 

 tumn; the leaf -stalk is stout, grooved, 6 to 12 mm. long. The flowers appear 

 from February to May. The staminate catkins are hairy, about 3 cm. long; calyx 

 hairy, deeply lobed and yellowish green; stamens exserted, their anthers oblong, 

 notched, smooth and yellow. The pistillate flowers are solitary or several together; 

 involucre hairy; styles short and spreading. The fruit is sessile or short-stalked, 

 often produced in great profusion; nut broadly oval to ovoid, 18 to 30 mm. long, 

 brown and shining; cup nearly hemispheric, Ught green and hairy inside, embrac- 

 ing about one fourth of the nut, covered by small, hairy scales with sharp tips. 



The wood is hard, strong but brittle, close-grained, dark brown; its specific 

 gravity is about 0.89; it checks badly and is little used except for fuel. 



This is one of the most beautiful of the California oaks. It is also called 

 Mountain white oak. Rock oak. White oak, Hill oak, and Blue oak. 



California Rock Oak. 



