WILLOW FAMILY 199 



75. S. saximontana Rydb. A densely cespitose, creeping undershrub 

 rarely over 5 cm. high; leaf-blades light green above, glaucous beneath, glabrous 

 1-2 cm. long, oblong or elliptic, commonly acutish at both ends; aments at the 

 ends of the leafy branches, 1-2 cm. long, loosely flowered; capsule ovoid, densely 

 grayish pubescent with short hairs, sessile, 3 mm. long; style obsolete S 

 reticulata Porter & Coulter, not L. S. aemulans v. Seem. ROCKY MOUNTAIN 

 WILLOW. High mountain tops: N.M. Nev. Wash. Alta. Alp. Mont 

 Jl-Au. 



76. S. nivalis Hook. A cespitose, creeping undershrub, 1-5 cm. high; leaf- 

 blades oval or orbicular, 1 cm. long or less, glabrous, entire, dark green above, 

 glaucous beneath; aments at the ends of the leafy branches, 1 cm. long or less, 

 few-flowered; capsule grayish, pubescent with short hairs, about 3 mm. long, 

 sessile. SNOW WILLOW. High mountains: B.C. Wash. Mont. Alta. Alp 

 Jl-Au. 



FAMILY 31. FAGACEAE. BEECH FAMILY. 



Monoecious trees or shrubs, with simple leaves. Staminate flowers in 

 elongate or head-like aments; calyx of 4-7 partially united sepals; stamens 

 4-20. Pistillate flowers in longer or shorter spikes; calyx of partly united 

 sepals. Gynoecium of 3-7 united carpels; styles as many, but usually only 

 one ovule maturing. Fruit a one-seeded nut, enclosed or seated in a scaly 

 or spiny, in ours cup-like imvolucre. 



1. QUERCUS (Tourn.) L. OAK. 



Trees or shrubs, with hard coarsely grained wood. Leaf-blades entire, 

 toothed, or lobed, firm-membranous or leathery, sometimes evergreen. Stamin- 

 ate aments elongate, drooping, clustered; calyx campanulate, 4-7-lobed; stamens 

 6-12; filaments filiform. Pistillate flowers solitary or in lax spikes; calyx urn- 

 shaped or cup-shaped. Ovary usually 3-celled; styles 3; ovules 2 in each cell, 

 but seldom more than one maturing in each pistil. Fruit a leathery, 1-seeded 

 nut (acorn), partly enclosed in an accrescent scaly involucre (cup). 



Leaves lobed or divided, not evergreen; lobes rounded, obtuse or acute, but not spinulose- 



tipped. 

 Leaves bright green, early deciduous. 



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



Upper scales of the cup not prolonged. 



Mature leaves softly pubescent, almost velvety beneath, deeply divided. 

 Scales of the cup thin, not much thickened on the back. 



2. Q. submollis. 



Scales of the cup corky-thickened on the back. 3. Q. utahensis. 



Mature leaves glabrate, puberulent, or somewhat pubescent, but not velvety 



beneath. 

 Cup flat, covering less than one-fourth of the acorn. 



4. Q. Vreelandii. 

 Cup hemispheric, covering one-third to one-half of the acorn. 



Mature leaves very thin, glabrate beneath or puberulent only on the 

 veins; cup covering about one-half of the acorn. 



5. Q. leptophylla. 

 Mature leaves firm, puberulent beneath; cup covering about one-third 



of the acorn. 

 Leaves mostly oblong in outline, lobed half way to the midrib or 



less, rather dull. 6. Q. Gunnisonii. 



Leaves obovate in outline, divided deeper than half way to the mid- 

 rib, very shining above. 



Lobes of the leaves broadly oblong, rounded at the apex. 



7. Q. Gambellii. 

 Lobes of the leaves ovate or triangular, acute. 



8. Q. novomexicana. 

 Leaves pale or bluish green, more persistent. 



Leaves broadly obovate, with narrow sinuses. 9. Q. Eastwooaiae. 



Leaves oblong-obovate, or elliptic; sinuses broad. 



Lobes oblong-ovate, obtuse or acutish, not mucronate. 



10. Q. venustula. 



Lobes triangular-ovate, mucronate. 11. Q. Fendleri. 



Leaves persistent, usually evergreen, entire, sinuate or dentate, or if more deeply lobed, 



the lobes with spinulose tips. 

 Cup hemispheric; acorns barrel-shaped. 



