186 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



tic, typically acute, subcordate and typically entire, very short-petioled ; atom 

 round, subincluded, scarcely 10 nun. in diameter, tlie rounded cup with acute 

 appressed scales. 



45. Quercus engelmanni * Greene in Grc^eue & Kellogsr, III. Wi'st Anier. Oaks 32. 

 1889. 



Southeastern California; type locality, between San Diego and Los Angeles; 

 said to reach adjoining Baja California. 



A moderate-sized tree very like the folI()\\iug, except in its broader leaves, 

 but of distinct geographic range; wood hard, strong but brittle, close-grained, 

 brown, its specific gravity about 0.94. 



The wood is said to check badly in drying and to be useful only for fuel. 



46. Quercus oblongifolia Torr. in Sitgreaves, Rep. ZuSii & Col. 173. 1853. 

 Chihualiua and Sonora. Arizona ; type from " western New Mexico." 

 Moderate-sized tree with slender, glabrescent, often pruinose twigs and small 



red buds with ciliate scales; leaves (deciduous?) small (usually 1 to 2 cm. 

 wide and 3 to 4 cm. long), glabrous, paler beneath, elliptic or oblong, rounded 

 at both ends or subcordate, entire or coarsely and crenately few-toothed, the 

 usually pruinose petiole short ; acorn elongate-ovoid, 10 to 1.5 nmi. in diameter, 

 one-third included, the half-round cup with rather broad and blunt, keeled, ap- 

 pressed scales ; wood hard and strong but brittle, very dark brown, heavy. 



47. Quercus grisea Liebm. Overs. Dansk. Vid. Selsk. Forh. 1854: 171. 18.54. 

 iJliihuahua, and apparently to Zacatecas. Western Texas, the type locality 



iiot specified. 



Shrub or small tree with slender tomentose twigs and small round red buds 

 with puberulent outer scales; leaves deciduous, small (scarcely 2 cm. wide 

 and 4 cm. long), thin, blue-green, minutely puberulent above and dull, though 

 glossy when abraded, stellate-scurfy beneath, elliptic or ovate, mucronately 

 subacute, often cordate, short-petioled, entire; acorns paired on a short slender 

 peduncle, ellipsoid, 8 mm. in diameter, 12 mm. long, scarcely one-third included, 

 the half-round cup with rather acute appressed scales. "Encina prieta," " en- 

 cina blanca " (Durango, Palmer). 



The wood is useful only for fuel. 



48. Quercus pungens Liebm. Overs. Dansk. Yid. Selsk. P^orh. 1854: 171. 1854. 

 Quercus unduJata pnngeois Engelm-. Trans. Acad. Sci. St. Louis 3: 392. 1876. 

 Chihuahua. New Mexico. 



Shrub or small tree with sUMuler tonientulose twigs; leaves deciduous, small 

 (scarcely 2 cm. wide and 3 cm. long), from scurfy glabrescent, crisped, elliptic, 

 pungently acute, rounded at base, very short-petioled, with about 4 large 

 pung(>nt deltoid teeth on each side; acorn ovoid, scarcely 8 mm. in diameter and 

 12 mm. long, half included, the roundtnl cup with small appressetl scales. 



49. Quercus pringlei Seemen, Bot. Jahrb. Engler 29: 96. 1900. 

 Coahuila ; type locality, in the Carneros Pass below Saltillo. 



Shrub with slender subglabresccnt twigs and minute round glabrous buds; 

 leaves (deciduous?) very small (scarcely 1 cm. wide and 2.5 cm. long), glab- 

 rous, lance-elliptic, subaristately acute, rounded at base, mostly entire, the 



* George Engelmann (1809-1884), a native of Germany, lived most of his life 

 at St. Louis, Missouri, where he was engaged in the practice of medicine. An 

 enthusiastic botanist, Engelmann devottxl most of his botanical labors to the 

 study of the more difficult groups of plants, such as the Cactaceae, Yucca, 

 Agave, Quorciifi, etc. lie describcnl many IVIexican species of these and other 

 groups. 



