246 TREES OF NORTH AMERICA 



replaced by the var. chesosensis Sarg. differing in the acuminate lobes of the leaves and 

 smaller cups of the fruit; known only on the dry rocky slopes of the Chesos Mountains, 

 Brewster County, Texas; and by the var. stellapila Sarg., differing in the presence of fas- 

 cicled hairs on both surfaces of the mature leaves and on the branchlets of the year; above 

 Fort Davis, Jeff Davis County, Texas. 



4. Quercus ellipsoidalis E. J. Hill. Black Oak. 



Leaves elliptic to obovate-orbicular, acute or acuminate, truncate or broadly cuneate at 

 base, deeply divided by wide sinuses rounded in the bottom into 5-7 oblong lobes re- 

 pandly dentate at apex, or often, especially those of the upper pair, repandly lobulate, 

 when they unfold slightly tinged with red and hoary-tomentose, soon becoming glabrous 

 with the exception of small tufts of pale hairs in the axils of the principal veins, at matur- 

 ity thin and firm, bright green and lustrous above, paler and sometimes entirely glabrous 

 below, 3'-5' long, 2|'-4' wide, with a stout midrib and primary veins and prominent re- 

 ticulate veinlets; late in the autumn turning yellow or pale brown more or less blotched 



Fig. 226 



with purple; petioles slender, glabrous or rarely puberulous, l|'-2' in length. Flowers: 

 staminate in puberulous aments l^'-2' long; calyx campanulate, usually tinged with red, 

 2-5-lobed or parted into oblong-ovate or rounded segments, glabrous or slightly villose, 

 fringed at apex with long twisted hairs, about as long as the 2-5 stamens, with short fila- 

 ments and oblong anthers; pistillate on stout tomentose 1-3-flowered peduncles, red, their 

 involucral scales broad, oblong, acute, hairy; calyx campanulate, 4-7-lobed, ciliate on the 

 margins. Fruit short-stalked or nearly sessile, solitary or in pairs; nut ellipsoidal to sub- 

 globose, chestnut-brown, often striate and puberulous, inclosed for one third to one half its 

 length in a turbinate or cup-shaped cup gradually narrowed at base, thin, light red-brown, 

 and covered by narrow ovate obtuse or truncate brown pubescent closely appressed scales. 

 A tree, 60-70 high, with a short trunk rarely 3 in diameter, much forked branches 

 ascending above and often pendulous low on the stem, forming a narrow oblong head, 

 and slender branchlets covered at first with matted pale hairs, bright reddish brown during 

 their first winter, becoming dark gray-brown or reddish brown in their second season. Win- 

 ter-buds ovoid, obtuse or acute, sometimes slightly angled, about \' long, with ovate 

 or oval red-brown lustrous slightly puberulous outer scales ciliate on the margins. Bark 

 thin, light yellow internally, close, rather smooth, divided by shallow connected fissures 

 into thin plates, dark brown near the base of the tree, dull above, gray-brown and only 

 slightly furrowed on the large branches. 



