3o6 



The Oaks 



A hybrid with the Turkey oak, Q. Cateshcei Michaux, is reported from Florida, 

 and one with the Spanish oak Q. triloba Michaux, from South Carolina. 



This tree is also known as High ground willow oak. Sand jack, Turkey oak, 

 Shin oak. Cinnamon oak, and Blue jack. 



23. WHITE LEAF OAK Quercus hypoleuca Engelmann 



Usually a small tree, sometimes a shrub, occurring among coniferous trees in 

 the mountains of southern Arizona, New Mexico, western Texas and northern, 



Mexico, attaining a maximum 

 height of 18 meters, with a 

 trunk diameter of 4 dm. It is 

 also called Mexican oak. White- 

 leaved oak, and Lance oak. 



The branches are slender 

 and spreading, the tree mostly 

 round-topped. The bark is up 

 to 2.5 cm. thick, deeply fissured 

 into broad rough ridges, with a 

 thick scaly, nearly black sur- 

 face. The twigs are stout and 

 stiff, velvety at first, becoming 

 nearly smooth, reddish brown, 

 sometimes glaucous and finally 

 almost black. The .winter buds 

 are ovoid, blunt, 3 mm. long, 

 their scales brown and pale 

 margined. The leaves are lan- 

 ceolate, oblong- lanceolate or 

 elhptic, 5 to 10 cm. long, sharp, mostly bristle-pointed, narrowed and wedge- 

 shaped or rounded at the base, thickened and revolute on the entire, wavy or 

 shghtly toothed margin, the teeth often bristle-pointed; they are rather thick, 

 yellowish green and shining with a slender midrib above, strikingly white-woolly 

 and strongly veined beneath, turning yellow or brown, but persistent until after 

 the new leaves appear, when they gradually fall off. The leaf-stalks are stout, 

 flattened, much thickened at the base, 3 to 10 mm. long. The flowers appear from 

 March to May, the staminate in slender, hairy catkuis 7 to 12.5 cm. long, their 

 calyx reddish and hairy, the 4 or 5 lobes ovate and blunt; stamens 4, much ex- 

 serted; anthers ovate, sharp-pointed, smooth, yellow. The pistillate flowers are 

 sessile or nearly so, involucral scales and calyx- lobes softly hairy; styles recurved, 

 red. The fruit, ripening in the summer of the second season, is usually sohtary 

 and nearly sessile; nut ovoid, 15 to 18 mm. long, brown, hairy at the apex, its 

 shell thick, white-w^oolly inside; cup broadly top-shaped to hemispheric, 10 to 13 



Fig. 258. White-leaf Oak. 



