12 
SALICACEAE. 
. What is called the weeping willow here is really a com- 
plex including not only Salix babylonica but a series of usu- 
ally hardier hybrids of that species. 
i 
2. 
10. 
Lig 
12. 
13. 
Weeping. 2. 
Not markedly weeping. 4. 
Twigs very slender, glabrous. 3. 
Twigs stout: villous. 
(Kilmarnock willow). S. caprea pendula. 
. Buds alternate. (Weeping willow). (1). S. babylonica. 
Buds often opposite. (Purple willow). S. purpurea. 
. Buds large (5X10 mm.). 5. 
Buds moderate (4-6 mm. long). 7. 
Buds small (scarcely 3 mm. long). 9. 
. Buds rather sharply 2-winged. 6. 
Buds plano-convex. (2). S. missouriensis. 
. Buds green-and-red: planted. 
(Goat willow). (3). S. caprea. 
Buds blackish: native. (Pussy willow). S. discolor. 
. Buds frequently opposite. S. purpurea. 
Buds always alternate. 8. 
. Twigs glossy olive, glabrous. (Shining willow). S. lucida. 
Twigs dull, velvety. S. incana. 
. Trees: Twigs mostly glabrescent. 10. 
Shrubs: twigs gray-velvety. 13. 
Twigs olive-green. 11. 
Twigs golden. (Golden willow). S. vitellina. 
Twigs red. (Red-twigged willow). 
: S. vitellina Britzensis. 
Large open trees. 12. 
Slender, pole-like. (Sand-bar willow). S. longifolia. 
Trunks mostly clustered. (Black willow). S. nigra. 
Trunk single: twigs sometimes velvety. 
(White willow). S. alba. 
Buds 3 mm. long. (Prairie willow). S. humilis. 
Buds 2 mm. long. (Dwarf gray willow). (6). S. tristis. 
