SALICACEAE (WILLOW FAMILY) 



129 



Stamens 2, filaments hairy below; leaves linear or narrowly 



elliptical, remotely denticulate; shrubs 



Scales not pale yellow, mostly brownish to black, persistent. 

 Styles none; minute prostrate plant ..... 

 Styles distinct; erect or ascending shrubs. 



Styles 0.3-0.7 mm. long; aments pedunculate; leaves and 



capsules glabrous 



Styles 1-2.5 mm. long (sometimes shorter in No. 18), leaves 

 more or less tomentose, at least above; capsules gla- 

 brous to tomentose. 



Styles 1-1.5 mm. long; aments pedunculate (if sessile, 

 the leaves not glandular) ...... 



Styles 1.5-2.5 mm. long; aments stout, sessile; leaves 

 glandular .... 



CAPSULES HAIRY. 



Scales yellow, deciduous; filaments hairy below; styles none (in 

 our species) ......... 



Scales not yellow, mostly brown or black, at least at the tip, 



persistent. 

 Styles elongated, 0.5-2 mm. (over 1 mm. long, except in one 



species of Commutatae). 



Leaves usually gray-tomentose on both sides, sometimes 



on the upper surface only; aments mostly on long 



leafy peduncles; capsules gray- or white-tomentose. 



Capsules thinly villous-tomentose; stigmas entire, short 



(two species of) ....... 



Capsules densely white-tomentose; stigmas entire or usu- 

 ally divided, much elongated, about 1 mm. long . 

 Leaves glabrous on both surfaces or densely silvery- 

 pubescent on the lower surface only; aments dense, 

 sessile or on short, leafy peduncles; capsules silvery- 

 pubescent. 



Leaves densely clothed with a fine satiny pubescence 

 below, glabrate above; aments on short leafy pe- 

 duncles ......... 



Leaves glabrous on both surfaces, bright green; aments 

 closely sessile ....... 



Style obsolete, or only 0.2-0.3 mm. long. 

 Tall erect shrubs; capsule conic-rostrate. 



Aments stout, dense, sessile or subsessile; scales dark, 

 long-villous; pedicel short or none; stigmas long, 



slender 



Aments slender and lax, the staminate small, on short 

 leafy peduncles; scales pale, thinly villous; pedicel 

 elongated; stigmas short ..... 

 Low depressed or creeping shrubs; capsules short, ovate- 

 conic, subsessile; aments small, few-flowered, short- 

 peduncled; leaves obovate, reticulate on both sides . 



III. LONGIFOLIAE. 



IV. RETUSAE. 



V. CORDATAE. 



VI. COMMUTATAE. 

 VH. LANATAE. 



IH. LONGIFOLIAE. 



VI. COMMUTATAE. 

 Vin. ARCTICAE. 



IX. ARGENTEAE. 

 X. PHYLICIFOLIAE. 



XI. CAPREAE. 



XII. ROSTRATAE. 

 Xin. RETICULATAE. 



AMYGDALINAE. Trees 3-15 m. high; bark brown; twigs long and slender, 

 often drooping, usually gray: leaves linear-lanceolate to broadly lanceolate, 

 acuminate, closely and finely serrulate, glabrous; stipules small and decidu- 

 ous or none: aments coetaneous, slender cylindrical, terminal on lateral leafy 

 twigs: scales deciduous, light-yellow, lanceolate or broader, mostly glabrous 

 outside, crisp-villous within: stamens 8-7, filaments hairy below: capsule 

 small, glabrous, pedicellate; styles 0.3-0.5 mm. long; stigmas short. 



Leaves linear-lanceolate, deep green beneath . 

 Leaves lanceolate or broader, glaucous beneath 



1. S. nigra. 



2. S. amygdaloides. 



1. Salix nigra Marsh, Arb. Am. 139. 1785. Dark green; twigs grj 

 brownish: leaves linear-lanceolate, long-acuminate, often falcate, deep 



gray or 

 green 



on both sides, 6-11 cm. long, 7-12 mm. wide (often ob lanceolate while un- 

 folding) ; petioles short, 3-6 mm. long: staminate aments yellow, 2-5 cm. long; 

 pistillate aments 2-6 cm. long in fruit: capsules ovate or ovate-lanceolate, 3-4 

 mm. long; pedicels 1-1.5 mm. long. BLACK WILLOW. (S. Wrightii Anders, 

 founded on a monstrous form with compact and distorted aments.) River 

 banks, common; plains of eastern Colorado to New Mexico and California. 



2. Salix amygdaloides Anders. Ofv. Handl. Vet. Akad. 114. 1858. Yel- 

 lowish green; twigs gray or the youngest yellow: leaves lanceolate to ovate- 

 lanceolate (frequently obovate or broadly oblanceolate and obtuse when un- 

 folding), gradually or abruptly acuminate, green above, glaucous beneath, 

 5-12 cm. long, 1.5-3 cm. wide; petioles slender, 5-15 or 20 mm. long: staminate 



ROCKY MT. EOT. 9 



