FAGACEAE (BEECH FAMILY) 141 



branches during the winter, opening in the spring before the leaves develop: 

 fertile aments erect, their scales becoming woody, persistent for a time after 

 the small, compressed, scarcely winged nuts have fallen. The common ALDER 

 on all the streams of this region. 



30. FAGACEAE Drude. BEECH FAMILY 



Shrubs or trees, with deciduous or evergreen alternate petioled leaves. 

 Flowers monoecious; the staminate in aments; the pistillate solitary or few in 

 a cluster, subtended by an involucre (of more or less united bracts) which 

 becomes a bur or cup. Petals non ",, Staminate flowers with a 4-7-lobed 

 perianth and 4-20 stamens on s*. r der filaments; the pistillate with an urn- 

 shaped perianth adnate to the f-> -jelled ovary; ovules 1-2 in each cell, only 

 1 maturing; styles linear, as many as the cells in the ovary. Fruit a 1-seeded 

 nut, with coriaceous or bony exocarp. 



1. QUERCUS L. OAK 



Shrubs or trees. Leaves in ours mostly deciduous. Flowers small, green or 

 yellowish; the staminate numerous, in slender drooping aments; the pistillate 

 solitary, in many-bracted involucres. Staminate flowers subtended by 

 caducous bracts, consisting of a mostly 6-lobed perianth and 5-12 stamens. 

 Pistillate flowers with an urn-shaped calyx adnate to a 3-celled ovary. Fruit 

 consisting of the imbricated and united bracts of the involucre (cup), sub- 

 tending or nearly inclosing the coriaceous nut (acorn). 



Upper scales of the cup with caudate prolongations . . . 1. Q. macrocarpa. 



Upper scales of the cup not prolonged. 

 Leaves deciduous, lobed or divided. 



Densely and softly short-villpus beneath 2. Q. utahensis. 



Glabrate or pubescent (especially on the veins) beneath. 



Cup shallow, covering less than one fourth of the nut . . 3. Q. Vreelandii. 

 Cup deeper, covering more than one fourth of the nut. 



Leaves thin and almost glabrous . . . . . . 4. Q. leptophylla. 



Leaves firm, puberulent beneath. 



Nut obtuse . . . . . . . . . 5. Q. Gunnisonii. 



Nut acute 6. Q. Gambellii. 



Leaves persistent, from nearly entire to undulate toothed . . 7. Q. undulata. 



1. Quercus macrocarpa Michx. Hist. Chens Am. No. 2. 1801. Becoming 

 a large tree with gray flaky bark: leaves variable, obovate or oblong-obovate, 

 irregularly lobcd, or' pinnatifid, or deeply undulate, at maturity green and 

 shining above, grayish-white tomentulose below, 8-16 cm. long: styles short: 

 fruit subsessile; cup subglobose or hemispheric, 14-20 mm. in diameter; its 

 bracts floccose, hard, thick, the upper subulate-tipped forming a fringe around 

 the ovoid acorn, which is from jhalf to almost wholly immersed in the cup. 

 BUR OAK or MOSSY-CUP. This valuable tree comes into our range in the 

 Black Hills of South Dakota and Wyoming, where it usually attains fair size, 

 though occasionally scarcely more than a shrub. 



2. Quercus utahensis (DC.) Rydb. Bull. N. Y. Bot. Card. 2: 202. 1901.* 

 A small tree often 10 m. high or more or sometimes only a shrub: bark of 

 young branches light brown and pubescent, bark of the older branches brown 

 or gray; bark of the trunk rough and furrowed: bud-scales thin, brown, some- 

 what hairy and puberulent: petioles about 1 cm. long, puberulent; leaf-blade 

 6-10 cm. long, broadly obovate, deeply divided, often to near the midrib; 

 lobes oblong, rounded at the apex, the larger usually again lobed or undulate; 

 upper surface sparingly stellate, in age glabrate, dark green and glossy; lower 



* In his paper, "The Oaks of the Continental Divide," north of Mexico, Rydberg has 

 given the species most exhaustive treatment. Indebtedness to his descriptions is gratefully 

 acknowledged. 



