WILLOW FAMILY 63 



Bractlets yellow or brown; stipes 3-4 times as long as the nectaries; style less than 



0.5 mm. long. 54. S. argyrocarpa. 



Bractlets fuscous ; stipes less than twice as long as the nectaries. 



Style about 0.5 mm. long; bractlets obtuse. 65. S. arbusculoides. 



Style 1-2 mm. long. 



Branches without a bloom; leaves tomentose beneath. 



56. S. pellita. 

 Branches with a bloom; leaves white-silky beneath. 



Aments peduncled and leafy-bracted. 57. S. subcoerulea. 



Aments sessile and naked. 58. S. pachnophora. 



X. Abcticae. 

 Aments on leafy peduncles. 



Leaves grayish villous on both sides, less so on the upper. 

 Twigs white-villous or silky; branches yellow or grayish. 



Leaves villous; capsules densely pubescent. 59. S. brachycarpa. 



Leaves silky; capsules finely and sparingly pubescent. 



60. S. idahoensis. 

 Twigs puberulent; branches usually purplish. 



Bractlets black or with blackish tips. 



Leaves oblong, 2-3 cm. long; bractlets obovate; branches divergent. 



61. S. pseudolapponum. 

 Leaves oblanceolate or obovate, 3-6 cm. long; bractlets oblong; branches 



ascending. 62. S. glaucops. 



Bractlets yellow, oblong. 63. S. SeemannU. 



Leaves glabrate or when young covered with white hairs parallel to the midrib. 

 Shrubs not creeping, although often depressed. 



Leaves broadly oval, often minutely glandular-dentate. 



64. S. subcordata. 

 Leaves narrower. 



Leaves oblong or oblanceolate, or ovate. 



■ Leaves 2-4 cm. long; capsule 3-5 mm. long. 



Bractlets yeUow or brown, oblong; leaves elliptic or oblanceolate, 



thin, darkening in drying; twigs purple. 65. S. desertorum. 

 Bractlets fuscous at the apex ; leaves oblong, not blackening in 

 drying. 61. S. pseudolapponum. 



Leaves 4-6 cm. long. 



Bractlets fuscous; leaves elUjptic or oblong, obtuse or acute, usually 



reticulate; glabrous only in age. 62. S. glaucops. 



Bractlets yellow or brown; leaves usually short-acuminate, glabrous 

 except when very young, not reticulate. 

 Leaves entire or sparingly glandular-denticulate, oblanceolate. 



66. S. Austinae. 

 Leaves finely serrulate, elliptic, lanceolate, or oblanceolate. 



67. S. MacCalUana. 

 Leaves linear-lanceolate. 



Shrubs creeping; arctic or alpine. 



Leaves obovate or oblanceolate; aments many-flowered^ 



Leaves narrowly oblanceolate; aments few-flowered. 

 Aments naked, from lateral buds. 



Leaves oblanceolate, strongly veined. 

 Leaves elliptic, not strongly veined. 



XI. Eeticulatae. 



Leaves covered beneath with long white silky hairs. 

 Leaves at least in age not silky. 



Leaf-blade over \ cm. long; aments comparatively many-flowered. 



Filaments very hairy on the lower part; leaves strongly reticulate; bracts broadly 

 obovate, fuscous, the upper portion almost glabrous. 



74. S. orbicularis. 

 Filaments almost glabrous; leaves less strongly reticulate; bracts cuneate-oblong, 

 yellow, almost glabrous. 75. S. saximontana. 



Leaf-blade 1 cm. or less long; aments few-flowered; bractlets yellow, almost glabrous. 



76. S. nivalis. 



Family 31. FAGACEAE. Beech Family. 



1. QUERCUS (Tourn.) L. Oak. 



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. 



