276 TREES OF NORTH AMERICA 



becoming darker in their second and third years; frequently, especially in western 

 Texas, small and shrubby and often forming extensive thickets. Winter-buds 

 broadly ovate or oval, acuminate, ^'-^' long, with light chestnut-brown closely 

 imbricated puberulous scales. Bark \'-% thick, separating into long and narrow 

 plate-like scales, silvery white tinged with reddish brown on the surface. Wood 

 heavy, hard, strong, brittle, brown, with thick lighter colored sapwood; most valuable 

 east of the Mississippi River. 



Distribution. Rich limestone prairies of central Alabama and Mississippi, banks 

 of the Red River at Shreveport, Louisiana, and in Texas on dry limestone banks of 

 streams and rocky bluffs from the neighborhood of the city of Dallas westward to 

 the central part of the state and southward to the mountains of Nuevo Leon. 



38. Quercus undulata, Torr. Scrub Oak. Shin Oak. 



Leaves oblong, acute or rarely rounded at the apex, broad and rounded or cor- 

 date or rarely cuneate at the base, sinuate-dentate, entire, pinnatifid, lobed or spi- 

 nescent, when they unfold coated with hoary tomentum, at maturity thick and firm, 

 light blue-green, more or less covered with stellate hairs above and clothed below 

 with pale or yellow pubescence, l'-3' long, '-' wide, with pale slender midribs 

 and few conspicuous primary veins running to the points of the teeth or arcuate and 

 united with the thickened and revolute margins, deciduous in the autumn at the 

 north and at high elevations, southward often remaining on the branches until the 

 appearance of the leaves of the following year; their petioles stout, pubescent or 

 tomentose, \'-V long. Flowers: staminate in tomentose aments l'-2' long; calyx 



hairy, divided into acute segments; pistillate sessile or raised on peduncles tomen- 

 tose like their involucral scales; stigmas red. Fruit solitary or in pairs, sessile or 

 on stout hoary peduncles sometimes nearly 2' long; acorn oval, rounded and rather 

 obtuse or acute at the apex, f'-l' long, inclosed for about one third its length in 

 a thick cup-shaped cup reddish brown and pubescent on the inner surface, hoary- 

 tomentose and covered on the outer by ovate acute scales usually thickened and 

 tumid toward its base and above the middle ending in thin bright red free ciliate 

 tips; seed sweet. 



A tree, occasionally 25-30 high, with a straight trunk 6'-8' in diameter, and 



