Salix pyrifolia is called balsam willow because its leaves and twigs have a resin which causes dried specimens to smell like balsam fir. Willow bark was long used as relief for pain and fevers -- it contains salicylic acid, the active agent in aspirin.
There are 28 verified occurrences, though most are of small populations, and only 5 occurrences which are ranked good to excellent. There are also 20 historical occurrences which need to be checked. In recent years this species has been found more often in the Adirondacks and St. Lawrence County, and could be removed from the rare plant list if additional populations are discovered.
New populations of Balsam Willow have been discovered in recent years. The species may be increasing, or, since most populations are small, and may occur alongside other Salix species, it may have been overlooked often until recently.
Most of the historical records of this species are from Essex and Franklin Counties, and have not been surveyed in recent years, while most new records are from St. Lawrence County. Surveys of the historically known locations are needed to ascertain the long-term trend of this species in New York.
Changes to the hydrology of wetlands could threaten individual populations, though Balsam Willow may also be able to colonize wetlands following disturbance.
In New York Salix pyrifolia has been found in a wide variety of northern wetland habitats, including large patterned peatlands, bogs, shrub swamps, headwater seeps in rocky upland forests, balsam flats, and openings in subalpine spruce-fir forests. It will also colonize wet openings created by power line right-of-ways or beaver activity (New York Natural Heritage Program 2008). Low thickets and borders of woods (Fernald 1970). Moist, wet or swampy ground (Gleason & Cronquist 1991). In wet places, particularly black spruce-tamarack bogs, alder swamps, and sandy shores of ponds, creeks, and lakes; also in damp sandy ditches (Soper 1982).
Salix pyrifolia is known from northern New York, chiefly from the Adirondacks and the St. Lawrence Valley.
Salix pyrifolia is found in the boreal forest zone of Canada, and reaches its southern limit in the northern forests of Minnesota, Wisconsin, Michigan, New York, and New England.
Balsam Willow is a tall ( up to 5 m) shrub or small tree of northern wetlands. Like all willows, the buds have only a single scale, the plants are dioecious (either male or female, but not both), and the flowers are borne in tight clusters called catkins. The twigs are glabrous, at first yellowish but becoming bright red when in sunlight. The leaves lack stipules (or have only minute and quickly deciduous ones 1-2 mm long), and are up to 10 cm long, with serrate to crenate margins, and are shiny above but glaucous with prominent veination underneath. The catkins emerge with or after the leaves, and have persistent dark brown scales 2 to 2.5 mm long. The male flowers are on peduncles 2 to 8 mm long, and have 2 stamens. Female flowers are on leafy peduncles 1 to 3 cm long.
Salix pyrifolia is best identified when mature fruit is present, though identification from mature leaves vegetative is also possible.
The leaves of Salix myricoides and S. eriocephala have pubescent petioles and persistent stipules with pale hairs and asymmetrical leaf bases. No other willow has leaves and buds that have a balsam-like fragrance.
Salix pyrifolia flowers in early June, and fruits persist into July. The leaves remain to the first frost.
The time of year you would expect to find Balsam Willow vegetative, flowering, and fruiting in New York.
Salix pyrifolia Anderss.
Argus, G.W. 2005. Guide to the Identification of the Genus Salix (Willow) in New England and New York. Unpublished manuscript.
Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.
Gleason, Henry A. 1952. The New Britton and Brown Illustrated Flora of the Northeastern United States and Canada.
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.
Little, E.L., Jr. 1979. Checklist of United States trees (native and naturalized). Agriculture Handbook No. 541. U.S. Forest Service, Washington, D.C. 375 pp.
Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.
New York Natural Heritage Program. 2020. New York Natural Heritage Program Databases. Albany, NY.
Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.
Soper, James H. and Margaret L. Heimburger. 1982. Shrubs of Ontario. The Royal Ontario Museum, Toronto, Canada, 495P.
Information for this guide was last updated on: January 22, 2009
Please cite this page as:
New York Natural Heritage Program. 2020. Online Conservation Guide for Salix pyrifolia. Available from: https://guides.nynhp.org/balsam-willow/. Accessed September 25, 2020.