on: 
ol. 
30. 
ao. 
37. 
37. 
THE WILLOWS OF OHIO. ual 
28. Leaves distantly serrate with incurved teeth, not 
revolute. S. discolor. 
28. Leaves entire or very obscurely serrate, frequently 
revolute. 29: 
Margin undulate-revolute, veins very prominent below, 
bright green, only rarely completely glabrous. S. humilis. 
Margin not undulate, veins not raised below, purplish 
green. 30. 
30. Leaves elliptical, widest near the middle; dwarf shrub 
in bogs. S. pedicellaris. 
30. Leaves oblanceolate, widest above the middle; good- 
sized shrub; often planted. S. purpurea. 
Leaves with a strong marginal vein, smaller veins forming 
a very fine meshwork, leaves small, narrow, often fal- 
cate; tree with pendent branches. S. babylonica. 
Marginal if present not extending much below the middle 
Gt fue dleat.. 32. 
32. Leaves bluntly and coarsely or irregularly serrate with 
incurved teeth or entire; shrubs. 33. 
32. Leaves sharply serrate with projecting teeth. 36. 
Leaves extremely glaucous below, glossy above, broadly 
lanceolate or ovate; northern. S. glaucophylla. 
Leaves with a thin bloom beneath, not glossy. 34. 
34. Leaves lanceolate, long acute, venation regular; bark 
of branches green, smooth; arborescent. S. fragilis. 
34. Leaves mostly broadest above the middle, short acute; 
bark of branches brown, soon roughened. 35. 
( S. glaucophylla. 
Water shoots, blackening in drying 4 and 
l S. discolor. 
Well developed leaves, remaining green. S. discolor. 
36. Leaves held up by the stiff midrib so as to display their 
white under surfaces, broadly lanceolate or ovate, 
mostly glossy above and very heavily glaucous be- 
low; northern. S. glaucophylla. 
36. Leaves not held up against the twigs, mostly lanceo- 
later 2-37 
Primaries mostly forking and arching; sprawling shrubs. 38. 
Primaries mostly ascending without forking, arching or 
looping; arborescent, not sprawling except S. lon- 
gipes. 39. 
38. Leaves dull above, not very glaucous, almost always 
with a trace of hair on the veins above or below, 
quite sharply serrate, petiole stoutish. SS. cordata. 
