THE WILLOWS OF OHIO. 2 1 1 



28. Leaves distantly serrate with incurved teeth, not 

 revolute. 5. discolor. 



28. Leaves entire or very obscurely serrate, frequently 

 revolute. 29. 

 29. Margin undulate-re volute, veins very prominent below, 

 bright green, only rarely completely glabrous. 5. hwmilis. 

 29. 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. 5. purpurea. 

 31. Leaves with a strong marginal vein, smaller veins forming 

 a very fine meshwork, leaves small, narrow, often fal- 

 cate; tree with pendent branches. 5. baby Ionic a. 

 31. Marginal if present not extending much below the middle 

 of the leaf. 32. 

 32. Leaves bluntly and coarsely or irregularly serrate with 



incurved teeth or entire; shrubs. 33. 

 32. Leaves sharply serrate with projecting teeth. 36. 

 33. Leaves extremely glaucous below, glossy above, broadly 

 lanceolate or ovate; northern. 5. glaucophylla. 



33. Leaves with a thin bloom beneath, not glossy. 34. 



34. Leaves lanceolate, long acute, venation regular; bark 

 of branches green, smooth ; arborescent. 5. fragilis. 

 34. Leaves mostly broadest above the middle, short acute ; 

 bark of branches brown, soon roughened. 35. 



{ S. glaucophylla. 

 35. Water shoots, blackening in drying and 



[ 5. discolor. 

 35. 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. 5. glaucophylla. 

 36. Leaves not held up against the twigs, mostlv lanceo- 

 late. 37. 

 37. Primaries mostly forking and arching ; sprawling shrubs. 38. 

 37. Primaries mostly ascending without forking, arching or 

 looping; arborescent, not sprawling except 5. 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. 5. cordata. 



