188 SALICACEAE 



Capsule hairy. 



Filaments hairy; bractlets caducous; leaf-blades linear to lanceolate, not very veiny. 



IV. LONGIFOLIAE. 



Filaments glabrous, or if somewhat hairy, leaf-blades oval or orbicular, very veiny; 



bractlets persistent. 

 Capsule rostrate, distinctly stipitate; style none or short, always shorter than the 



stipe. 

 Stipe equalling or exceeding the bractlets; style 0.5 mm. long or less. 



VII. ROSTRATAE. 



Stipe shorter than the bractlets; style usually 1 mm. long. 



VIII. CAPREAE. 



Capsule scarcely rostrate, subsessile or, if stipitate, stipe shorter than the style. 

 Style evident, at least 0.5 mm. long. 



Leaves permanently silky or tomentose beneath. IX. ARGENTEAE. 



Leaves neither silky-white nor tomentose beneath. X. ARCTICAE. 



Style none; depressed or low shrubs, with entire strongly reticulate leaves. 



XL RETICULATAE. 



I. AMYGDALINAE. 

 Bractlets entire. 



Leaves narrowly lanceolate; petioles short. 



Bark of twigs brownish; aments long and lax; leaf-blades broadest below the mid- 

 dle, long-acuminate. 1. 5. nigra. 

 Bark of twigs light yellow; aments short and dense; leaf-blades usually broadest 



at or above the middle, short-acuminate. 2. S. Wrightii. 



Leaf-blades broadly lanceolate; petioles slender, 6-15 mm. long. 



3. 5. amygdaloides. 

 Bractlets denticulate. 4. S. laevigata. 



II. PENTANDRAE. 



Leaves narrowly oblanceolate, acute, drying blackish; bractlets of the staminate araents 



ovate, and of pistillate lanceolate, neither toothed. 5. S. erythrocorna. 



Leaves lanceolate to ovate; bractlets of the staminate aments obovate or spatulate, 



usually toothed; those of the pistillate aments oblong. 

 Bractlets densely white- villous ; stipe of the capsules scarcely twice as long as the 



nectaries. 6. S. serissima. 



Bractlets sparingly hairy; stipe of the capsules 3-4 times as long as the nectaries. 

 Leaves ovate-lanceolate or ovate; glands of the leaves very prominent; those on 



the petioles often stalked. 7. S. lucida. 



Leaves lanceolate; glands of the leaf-blades not very prominent; those on the 



petioles always sessile. 

 Leaf-blades usually less than 1 dm. long, green on both sides; aments short. 



8. S. Fendleriana. 

 Mature leaf-blades often 1 dm. long, glaucous beneath; aments elongate. 



9. S. Lyallii. 



III. ALBAE. 

 One species. 10. 5. alba. 



IV. LONGIFOLIAE. 



Capsule glabrous or slightly silky when young. 



Leaves with close serrations, glaucous and prominently veined beneath. 



11. S. melanopsis. 

 Leaves entire or with distant serrations, neither glaucous nor strongly veined beneath. 



Styles none. 



Leaves permanently silky. 



Leaves 3-5 mm. wide; ovary without a hairy swelling at the apex. 



12. S. exigua. 

 Leaves 2-3 mm. wide; ovary with a hairy swelling at the apex. 



13. S. stenophylla. 

 Leaves glabrous in age, or nearly so. 



Leaves linear-lanceolate; bractlets ovate or obovate, obtuse. 



14. 5. interior. 

 Leaves narrowly linear; bractlets lanceolate, acute. 



15. S. linearifolia. 

 Styles evident; aments dense; bractlets densely silky. 16. S. sessilifolia. 



Capsule permanently densely pubescent. 



Stigma sessile; leaves entire or nearly so. 17. 3. argophylla. 



Stigma on a distinct style, which is 0.5 mm. long; leaves dentate. 



18. S. macrostachya. 



V. CORDATAE. 



Leaves white-tomentose or white- villous beneath. 



Leaves entire, or minutely denticulate; aments 3-4 cm. long; bractlets silky-pilose. 

 Leaves permanently appressed-silky. 19. S. Sandbergii. 



Leaves in age glabrous and shining, at least above. 20. S. lasiolepis. 



Leaves usually crenate, villous, 3-8 cm. long; aments 3-6 cm. long; bractlets densely 



villous. 21. S. Hookeriana. 



Leaves glabrous or hairy, but not densely white-pubescent beneath. 

 Branches without a bloom. 



Capsule long-stipitate; stipe in fruit 1.5-6 mm. long, equalling or exceeding the 



bractlets; style 0.5 mm. long or less. 



Leaves dark green above; young branches not light yellow; aments on short 

 leafy branches. 



