CLASS XXI. ORDER VIII. 375 



390. QUERCUS. 

 duERCus ALBA. L. White Oak. 



Leaves somewhat equally pinnalifid, their seg- 

 ments oblong, obtuse, mostly entire ; cup bowl-shaped, 

 rough with tubercles ; acorn ovate. Mick. abr. 



The white oak has long been recognized among us as one of 

 the most valuable productions of our forests. Its name is derived 

 from the whiteness of the bark, a character by which it may be 

 distinguished at any season of the year. The leaves are divided 

 at their sides into a number of oblong, rounded lobes, which are 

 perfectly obtuse or entire, not terminating in points or bristles. 

 They are acute at base, their under side pale or glaucous, and, 

 when young, pubescent. The acorns are pretty large, ovate, 

 contained in the enlarged calyx, which forms a cup of a hemis- 

 pherical form, scaly and uneven on the outside. 



The wood of the white oak is superior to any species in the 

 northern states for strength and durability. Its timber is much 

 used in ship building, in frames, in mills, in wagons, ploughs, 

 &c., and for the staves and hoops of casks. The great consump- 

 tion of it for these purposes, has rendered it comparatively 

 scarce, so that poorer species are often substituted in the work- 

 shops of mechanics. 



QuRRCus BicoLOR. WHld. Swamp White Oak. 



Leaves oblong-ovate, downy, white underneath, 



largely toothed, entire at base, the teeth unequal and 



dilated; fruit on long peduncles. Mich. f. stib. syii. 



Syn. QuERCUS prinus tomentosa. Mich. 



QuERCUS PRINUS DISCOLOR. Midi. f. 



This species grows exclusively in swamps and low grounds. 

 It is often brought to market as fuel, and is easily distinguished 

 by its bark, which separates into large, flat scales or plates. 

 The leaves are inversely ovate or wedge shaped, not sinuated, 

 but bordered with a serpentine line, producing large, obtuse 

 teeth. They are smooth above, but white and downy underneath. 

 The acorns grow in pairs or single, on long stalks. They are 

 large, oval, with a rather small, hemispherical cup. 



