340 



The Oaks 



winter buds are brown, their scales thin and hairy. The leaves are broadly ob- 

 ovate in outline, 6 to lo cm. long, the 7 to 9 lobes oblong to obovate, seldom 

 lobed at the rounded apex, the sinuses deep and broad or narrow, shghtly rounded 

 at the bottom, the leaf base rather broad and rounded ; they are thick £ind firm, 

 dark green, shining and slightly hairy above, paler, brownish, softly downy, with 

 prominent venation beneath; the petiole is about i cm. long and slightly hairy. 

 The nearly sessile fruit ripens the first season; nut ovoid-oblong, 1.5 to 2 cm. 

 long, blunt-pointed, light brown; cup hemispheric, 12 to 15 mm. across, embrac- 

 ing about one haK the nut, covered with ovate, corky-thickened, hairy scales. 



60. COLORADO WHITE OAK — Quercus leptophyUa Rydberg 



This tree, known only from Colorado, grows along stream banks, especially in 

 canons. It is the largest oak of the State, reaching a height of 15 meters, with a 

 trunk diameter of about 7 dm. 



The bark is furrowed, rough and gray. The twigs are slightly hairy, purplish 



or brown, becoming smooth and 

 gray. The leaves are broadly 

 obovate in outline, i to 1.5 dm. 

 long, the 5 to 9 lobes oblong 

 to triangular, rounded or ob- 

 liquely notched at the apex, the 

 sinuses broad, sometimes reach- 

 ing half-way to the midrib and 

 rounded at the bottom, the base 

 broad or cuneate- tapering; they 

 are very thin and firm, light 

 green, sparingly hairy at first, 

 soon becoming smooth and 

 shghtly shining above, paler 

 and smooth except on the 

 prominent venation beneath; 

 the leaf-stalk is rather stout, about 1.5 cm. long. The fruit, ripening in the 

 autumn of the first season, is nearly sessile; nut broadly oblong, 12 to 15 mm. 

 long, blunt or depressed at the apex, embracing one half of the nut, covered by 

 ovate-lanceolate, shghtly thickened, blunt scales. 



Fig. 20 



• Colorado White Oak. 



61. ASHE'S OAK — Quercus Margaxetta Ashe 



While usually a shrub, this sometimes becomes a tree 10 meters tall. It occurs 

 in pinelands or open woods from Virginia to Florida and Alabama and is a near 

 relative of the Post Oak. 



The bark is very rough, the twigs rather stout, smooth, shining and reddish 



