138 Trans. Acad. Sci. of St. Louis. 



that followed immediately upon the closing scene of the Gla- 

 cial period, viz., the deposition of the loess. The willow 

 under consideration avoids low bottom lands, growing spar- 

 ingly, however, on the higher elevations of such lands. 



As observed in the limits already pointed out, it occurs as 

 a shrub or small tree, chiefly the latter. The undoubted 

 shrubby form is really very scarce in this region. Often, 

 when, at first, I thought here I have one, upon closer inspec- 

 tion, it proved to be only sprouts of several years growth 

 sprung from a stem or stems previously cut, or from a pros- 

 trate trunk covered with soil on occasion of flooding of the 

 gully or ravine. The banks being alluvium, trunks are up- 

 rooted and laid prone along the edges. In such case there 

 will be plenty of shrubs apparently. One can the better ap- 

 preciate such complication when the fact is recalled that this 

 willow, especially, by nature, hugs closely the water-courses. 

 Moreover, inasmuch as trees are small before they are big, 

 and as the habit of this willow is, frequently, to grow in a 

 clump, like Nigra, from a common center, it becomes a no 

 easy task, nay, often, an impossible one, to say whether the 

 example before you is a tree or shrub. 



As a tree, full grown, I think I may safely state the range, 

 in height, from 15 to 35 ft., in diameter from 3 to 7 in. Its 

 usual habit is to fork low, often near the ground, or from 3 to 

 8 ft. higher, or throw off branches within this distance ; but 

 if crowded, as in a grove, many may be noticed not giving off 

 any considerable branches for at least 20 ft. above the ground. 

 When growing in clump of 3 to 5 or more, one or two of the 

 stems may be 5 to 7 in. thick, and as high as the single stemmed 

 tree. 



The bark on all is light or dark grey, smooth, except towards 

 the base of old trunks, where it is roughish : Year-old twigs 

 if downy or tomentose, which is usually the case, are grey or 

 blackish ; if not downy or tomentose, greenish, greenish-yel- 

 low and blotched, or even yellow, or red on the side toward 

 the sun. The same shoot which, early in the season, puts out 

 with a hairy, tomentose vestment, will, in a second, prolonged 

 growth, later in the season, be perfectly smooth. The same 

 holds true of the buds. 



