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4 
Ww 
THE WILLOWS OF OHIO. 
FRAGILES, CRACK WILLOWS. 
Trees, originally introduced from Europe and though now 
freely escaped, still largely planted and often found growing in 
rows (except the Weeping Willow). The bark of the medium- 
sized branches is smooth, and yellow or greenish as distinguished 
from the rough brown bark of the Amygdalenae. The leaves of 
all the species are glaucous beneath and without stipules unless 
very young. The catkins are borne with the leaves on lateral 
branches; the stamens are normally only two; the capsules 
glabrous and green, in flower at least, like the Amygdalenae but 
unlike the other diandrous willows. 
The Fragiles are clearly intermediate between the polyan- 
drous tree-willows and the diandrous shrubs. But among them- 
selves their relationships are not so clear. By hybridisation and 
the importation of various horticultural varieties the group is 
very much confused and consists of many very closely similar 
forms. It has been the despair of many Botanists and one finds 
more mistakes in the determination of this group than in any 
other. 
Key. 
From habit. 
Growing in clumps. 
Bark of branches green. S. fragilis. 
Bark of branches yellowish green or yellow S. alba. 
Large trees, not in clumps. 
Branches long, drooping. S. babylonica. 
Branches not pendulous. 
Large branches and trunk disfigured by many ad- 
ventitious twigs, a tall tree with a central 
shaft, branches yellowish. S. alba. 
Without many adventitious twigs, a low broad 
topped tree without a central shaft, branches 
green. S. fragilis. 
From leaves. 
Leaves with a marginal vein, reticulations very fine, vena- 
tion irregular, leaf narrow, acuminate, often strikingly 
falcate, sharply serrate. S. babylonica. 
Without marginal, reticulations not so fine, venation regu- 
ular, leaf broader, not acuminate nor falcate. 
Plate IV. Salix fragilis. 
Leafy twig tpyical of our American form; the single broader leaf re- 
sembles more closely the European form; natural size; capsule enlarged 
three times. 
