bo 
~I 
On 
THE WILLOWS OF OHIO. 
species, especially in winter when it is leafless. In summer the 
long slender twigs sometimes give it almost the appearance of the 
Weeping Willow from which, however, it can be easily distin- 
guished by its leaves green, not glaucous. The winter buds are 
very small, less than 3 mm. long, broadly ovate, acute, commonly 
but not always without the mark of the leaf base across the back. 
The leaves commonly are about 10 cm. long by 1 wide, narrowly 
lanceolate with a very long attenuate-falcate tip, mostly very 
finely serrate, green and glabrous on both sides. The character- 
istic venation of the Amygdalenae is at its fullest development 
in Salix nigra. The marginal vein often runs almost to the very 
base and the secondaries and tertiaries blend into a system of 
meshes finer than in any other of our species. 
Sometimes broad, blunt leaves are found at the bases of 
lateral twigs but they are still easily recognized by their fine re- 
ticulation. The aments appear with the leaves, capsules glab- 
rous, short conic, short pedicelled, forming thin close cylindric 
catkins which, supported as they are by the characteristic leaves, 
resemble those of no other species. The staminate resemble 
very closely those of ‘S. amygdaloides (which see), stamens 5 or 
more, filaments pubescent. 
Everywhere throughout the state, Salix nigra is our com- 
monest willow. But it assumes a much more important role in 
plant society along the southern border than further north. 
There it attains its greatest size and at the same time becomes 
much more abundant than elsewhere. For long distances along 
the Ohio River it is almost the only native willow met with and 
occupies all the territory which in the north is divided up between 
several species. 
So far as Ohio is concerned it is perhaps the most constant 
and easily recognized of our willows but in the south it is almost 
identical with S. humboldtiana and is rather hard to separate 
from S. longipes. In the west it is represented by several 
variable varieties which seem to connect it with related forms 
and render it a very difficult subject indeed. 
Its typical habitat is along streams but it may be found in 
wet places generally though it seems to prefer moving to stagnant 
water and is much more infrequent in swamps. 
The variety ‘‘jalcata”’ is a form with narrower more falcate 
leaves. In my opinion it is scarcely worthy of consideration 
since it is not genetically different but is merely an accidental 
leaf variation without correlated variation in other characters 
Plate l. Sahx negra. 
Leaves of ordinary growth and of ranker growth with stipules; flowers 
and fruit typical; natural size; drawings of the flowers and capsule made 
with camera lucida and photographed, enlarged seven times. 
