Description:
This shrub is about 6-20' tall, forming single or multiple
trunks. Most branches are erect to ascending and little-branched. An
older shrub forms a gray-brown bark near the base that is slightly
rough and fissured, while the bark of upper branches and twigs is
reddish brown to brown and smooth. Actively growing stems are yellowish
green to light green
and either smooth, slightly
pubescent, or densely
pubescent (rarely the latter). The alternate leaves of these stems are
up to 4" long and
1½" across; they are ovate to narrowly ovate in shape and irregularly
crenate-serrate to nearly smooth along their margins. The upper leaf
surfaces are medium to dark green and hairless, while their lower
surfaces are hairless, glaucous, and whitened. Shrubs with pubescent
leaf undersides are probably hybrids. The slender petioles are up to ¾"
long and glabrous to slightly pubescent. At the base of some petioles
(particularly for vigorously growing shoots), there is a pair of large
stipules up to ¼" long and across; these stipules are somewhat cordate
in shape and either crenate-serrate or moderately lobed. On second-year
twigs, catkins of either male or female florets develop from sessile
scales. Pussy Willow is dioecious, with either all male or all female
florets on separate shrubs. As the male catkins begin to open, they are
covered with dense hairs that are silky gray. Shortly later, they
become larger in size (up to 1" long) and yellowish in appearance from
many stamens. Each male catkin consists of a dense mass of male
florets; each floret has 2 stamens. The female catkins are spike-like
racemes of female florets; these greenish catkins are 1-4" long at
maturity. Each female floret consists of a pistil with a pair of tiny
stigmata at its apex; the pistil is narrowly lanceoloid and canescent.
The blooming period occurs from early to mid-spring for about 2 weeks.
The female florets are replaced by seed capsules about 1/3" (6-8 mm.)
long.
During the summer, these capsules split open to release tiny seeds with
cottony hairs. These seeds are distributed by wind or water. The root
system is woody, branching, and shallow.
Cultivation:
The preference is full sun, wet to moist conditions, and sandy or
non-sandy soil with some decaying organic matter. The easiest method of
propagation is to cut off a branch and stick it into moist ground. The
branch will eventually form leaves at the top and develop roots
underground. It also possible to scatter the tiny seeds across the
ground, but it will take longer to develop a mature shrub. Because the
seeds remain viable for only a week or two, they must be sown
immediately.
Range &
Distribution: The native Pussy Willow is
occasional in NE
Illinois and uncommon or absent elsewhere in the state. Illinois lies
along the southern range limit of this primarily boreal species.
Habitats include openings in floodplain forests, soggy thickets,
marshes, shrub swamps, fens, low areas along rivers and other bodies of
water, wet prairies, and ditches. This shrub is found in both sandy and
non-sandy habitats. In areas that are prone to invasion by trees, some
disturbance is necessary to maintain populations of this species.
Faunal Associations:
The nectar and pollen of the florets attract mostly small bees and
flies. Other insects that visit the florets to a lesser extent include
honey bees and bumblebees, Ichneumon wasps, sawflies, butterflies,
beetles, and plant bugs. The following oligolectic Andrenid bees have
been observed visiting Pussy Willow: Andrena andrenoides,
Andrena erythrogaster, Andrena
illinoiensis, Andrena mariae, and Andrena
sigmundi. A large number of insects feed on the leaves or
branches of this and other willows. This includes the caterpillars of
butterflies, skippers, and moths (see Lepidoptera
Table), the grubs of long-horned beetles (Cerambycidae), leaf
beetles (see Leaf Beetle Table), aphids,
thrips, plant bugs, stinkbugs, and the larvae of some sawflies. Many of
these insects are an important source of food to various birds. Willows
are also eaten by vertebrate animals, including the Ruffed Grouse
(buds), tree squirrels (buds, seed capsules), the Wood Turtle and
Snapping Turtle (fallen leaves), muskrats (bark), beavers (bark, wood),
deer and elk (leaves, branches), and rabbits (bark, young saplings).
Some birds use willows as cover for their nests (Yellow Warbler,
Warbling Vireo), while beavers use willow branches in the construction
of their dams and lodges.
Photographic Location:
A wet sand prairie at the Iroquois County Conservation Area in NE
Illinois. The photographed shrub has an unusually hairy stem.
Comments:
This shrub should not be confused with the non-native Salix
caprea (Goat Willow). This latter species is often cultivated
and it is also called 'Pussy Willow.' The Goat Willow has even larger
male catkins than the native Pussy Willow, but it rarely escapes into
the wild. While it is rather variable across its range, the native
Pussy Willow can be distinguished from other similar willows by its
leaves: 1) they are more wide than the leaves of some willow species,
2) their margins are irregularly crenate-serrate to nearly smooth,
rather than finely serrated or entirely smooth, 3) its leaf undersides
are hairless, glaucous, and whitened, and 4) the large stipules at the
base of the leaf petioles are about as wide as they are across and they
are often persistent. Because the young stems of Pussy Willow can be
hairless, slightly pubescent, or even densely pubescent, their level of
hairiness is unreliable in making an accurate identification. The
leaves of Salix glaucophylloides (Blue-Leaved
Willow) are rather similar to those of Pussy Willow, however
Blue-Leaved Willow has leaves with finely serrated margins.