Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
Bogs, swamps, shores, stream banks, ditches, wet thickets and fields, rarely upland in sandy or rocky ground.
One of our commonest but most variable species, often hybridizing. Plants with mature branchlets and foliage glabrous or nearly so (var. discolor) are fairly readily recognized. Pubescent plants (var. latifolia Andersson) are almost equally abundant throughout the state; they may sometimes closely resemble S. humilis (and may in part even be a result of hybridization with that species). The mature aments in var. latifolia tend to be longer than in typical var. discolor, in contrast to the short aments of S. humilis. Vegetative material is more of a problem to identify, the differences in leaf shape and texture being rather subtle. The leaves of S. discolor have more of a tendency to be elliptic: those of S. humilis run more consistently to an oblanceolate or narrowly obovate shape and also tend to be more rugose and pubescent beneath. The normally dry upland habitat of S. humilis in this region is a helpful contrast with the moist habitat most typical of S. discolor.
A cultivated and occasionally escaped Eurasian species, S. caprea L. is the “Pussy Willow” of the florists, and with smooth wood will run to S. discolor in the keys. Young staminate material is readily distinguished by the very large, thick aments, which flower from the base to the apex. The leaves are very broad (sometimes almost orbicular) and densely gray-tomentose beneath. The Keweenaw Co. report in Michigan Flora (O. A. Farwell in 1888, MICH) is a poor specimen suggested by G. W. Argus as perhaps referable to a broad leaved individual of S. humilis.