THE WILLOWS OF OHIO. 291 



Key. 



Leaves narrow, not over 1 cm., sometimes very long, second- 

 ary, (auxilliary) aments very much younger than the primary; 

 forming dense clumps of slender stemmed shrubs. S. interior. 



Leaves often 1.5 cm. broad or more, not long in proportion, 

 secondary aments of about the same age as the primary, forming 

 a cymose cluster; low, bushy, not in close clumps; northern. 



5. interior zvheeleri. 



Salix interior Rowlee. Long-leaved Willow, Sandbar 



Willow. 



(S. longifolia and S. fluviatilis of the manuals in part.) 



The characteristic habit of this plant is to grow in clumps 

 about 4 meters high with a great many slender stems coming up 

 very close together from a common root system. These stems 

 are more slender than those of any other of our willows and 

 when the species assumes this habit it may be recognized 

 from a considerable distance. Unfortunately, however, it does 

 not always do so, but sometimes grows by itself as a bush or small 

 tree and then it can best be distinguished by its leaves. The 

 twigs are very slender, thickly branched and straight ascending 

 so that the stems have a peculiar brush-like appearance which 

 gives a pleasing softness to the landscape. The winter buds are 

 small and the twigs resemble those of the black willow more or 

 less closely as the bark is of about the same color. Many of the 

 buds are defective and drop off early in the autumn. The places 

 'of such are taken by small lateral buds which develop one on each 

 side of the old scar. This habit when present is characteristic. 

 It is largely responsible for the large number of small branches 

 which come out for there .thus arise two twigs instead of one at 

 each node. The leaves are sometimes very long (to 15 cm.) and 

 not more than 1 cm. wide, of almost the same breadth throughout , 

 straight linear-oblong, serrated, but with shallow distant spinu- 

 lose teeth. When young they are spatulate. The venation is 

 very characteristic except in young leaves as described above. 

 Sometimes they are very hairy even being covered with matted 

 wool persistent until very old, but often they are glabrous and 

 green as soon as they unfold. 



Plate VII. Salix interior and Salix interior wheeleri (marked W). 



Leafy branch of the narrow leaved form of 5. interior: flowers typical ; 

 two fruiting aments shown, one nearly glabrous, the other with densely 

 tomentose capsules; natural size; capsule enlarged three times. Variety 

 wheeleri typical cluster of staminate aments; the densely tomentose leaves 

 in the upper corner are from the form which connect with the species; 

 the larger broad glabrous leaves shown below are the extreme form of 

 the variety farthest from the species, natural size. 



