TREES AND SHRUBS. 



QUEECUS LEPTOPHYLLA, Eydb. 



Quercus leptophylla, Rydberg, Bull JST. T. Bot. Gard. ii. 205, t. 26, f. 1-2 (1901); Fl. 



Colorado, 98.— Britton & Shafer, N. Am. Trees, 340, f. 298. — Nelson, Coulter, Man. 



Rocky Mt. Bot. ed. 2, 142. 

 Quercus Gambelii, Sargent, Silva N. Am. viii. 33 (in part) (not Nuttall) (1895). 



Leaves oblong to oblong-obovate, cuneate or rarely rounded at the base, divided about half-way 

 to the midribs into from two to four pairs of acute or rounded lateral lobes entire or occasionally 

 furnished on the lower side with a small nearly triangular lobe, the terminal lobe short, entire, or 

 three-lobed; when they unfold thickly coated with hoary tomentum; about one-third grown when 

 the flowers open and then covered above with clusters of stellate hairs and toinentose below, and 

 at maturity thin, dark green, lustrous, and glabrous or nearly glabrous on the upper surface, 

 yellow-green and covered below by short white hairs most abundant on the midribs and veins, 

 from 6 to 15 centimetres long and from 4 to 10 centimetres wide; petioles slender, pobwoent, 

 from 1 to 3 centimetres in length; stipules spathulate, acute, gradually narrowed into a stipe-like 

 base, scarious, from 5 to 6 millimetres long, caducous; staminate flowers in slender villose 

 aments; calyx scarious, divided to the base into five or six narrow acute lobes; anthers as the 

 flowers open dark red-brown; pistillate flowers not seen. Fruit solitary or racemose, sessile or on 

 stout tomentose peduncles from 1 to 1.5 centimetres long; cup thin, hemispherical, from 1 to 1.3 

 centimetres in diameter, covered with acuminate only slightly thickened appressed scales densely 

 covered except at the base with hoary tomentum, enclosing for one-half or two-thirds of its 

 length the oblong ovate acorn abruptly narrowed and rounded at the base, gradually narrowed 

 at the rounded apex, usually from 1.4 to 1.6 centimetres in length. 



A tree, from 10 to 15 metres high, with a trunk from 4 to 6 decimetres in diameter, covered 

 with thick furrowed bark, broken on the surface into small appressed pale gray scales, heavy 

 spreading ashy-gray branches forming a round-topped head, and stout branchlets light red-brown 

 or purple and covered with stellate clusters of long hairs when they first appear, becoming light 

 brown and glabrous during their first season. 



Colorado: rich bottom-lands on the Cucharas River above La Veta, Huerfano County, common, 

 E. Bethel and C. S. Sargent, August 15, 1911, D. M. Andrews, October 5, 191 1, dune, L912. 



This species is the largest of all the Oaks of the Rocky Mountains of Colorado and the only species which grows on 

 bottom-lands, the others inhabiting dry hillsides. It is best distinguished from the other species of the region by the 

 thin scales of the cup which do not become thick and corky as in other specie* from th- interior of the BontiiKmt, with 

 the exception of Quercus submollis Rydberg, from Arizona, a species which, except in the thin scales of the cup, 

 resembles Quercus utahensis Rydberg. * 



1 A note on an interesting hybrid Oak may be added here. 

 Quercus ludoviciana, n. hyb. (Quercus pagodmfolia X PJiellos). 



Leaves early in the season dark green, lustrous and sparingly stellate-pubescent above and paler and thickly covered below 

 with small clusters of stellate hairs and densely villose on the midribs, at the base of the branch of the year from I 

 metres long and from 8 to 10 centimetres wide, oblong to oblong-obovate, cuneate at the base, usually nve-.obed the lateral lobes 

 acuminate, pointing forward, entire, separated by broad shallow sinuses, the upper lobes usually larger than those of the lower 

 pair, the terminal lobe long-acuminate, entire or more or less undulate ou the margins^tbe ^^.^f^J^, 

 narrower and less deeply lobed, and at the apex 

 cuneate or rounded and often unsymmetrical at t 



