Autumn Willow - Salix serissima
State Rank Reason (see State Rank above)
This willow is primarily found in Montana along the Rocky Mountain Front. Approximately half the occurrences are on lands managed in part for their conservation value. The species is primarily susceptible to impacts associated with heavy grazing and changes in the hydrology of the fens and wet meadows which it occupies.
Autumn Willow is a deciduous shrub growing up to 3 m tall, with bark ranging from grey on the older branches to straw colored on younger branches to shiny red-brown on the youngest twigs. Buds and leaves are arranged alternately on the stems. The leaf petioles usually have glands just below the leaf blades. The elliptic to lance-shaped leaf blades are 4-8 cm long and 1-2.5 cm wide and have long, tapered tips and fine glandular-tipped teeth on the margins; they are semi-glossy yellow-green to dark green above and dull and paler colored below. Flowers are borne in catkins which appear after the leaves; male and female flowers are borne on separate plants. The female catkins are 2-4 cm long and are borne on short, leafy branchlets. The bracts which subtend the female flowers are light yellow and hairy and fall off before the capsules mature. The capsules lack hairs and are 7-10 mm long and borne on stalks which are 0.5-2 mm long.
Flowering in June, fruiting in July-September.
Distinguishing characteristics include the finely-toothed, long taper-tipped, bicolored leaves with glandular petioles and the glabrous capsules which mature later than those of most other Montana willows.
NT to NL south to CO, SD, IN and NJ (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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(Observations spanning multiple months or years are excluded from time charts)
Fens and swamps in the valley and foothill zones.
Ecological Systems Associated with this Species
- Additional ReferencesLegend: View Online Publication
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- Argus, G. 2010. Salix. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 16+ vols. New York and Oxford. Vol. 7.
- Dorn, R. D. 1970. The Willows of Montana. Montana State University Herbarium, Dept. of Botany and Microbiology, Bozeman, Montana. 18 pp.
- Dorn, R.D. 2010. The genus Salix in North America north of Mexico. 59 pp.
- Lesica, P., M. T. Lavin, and P. F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- 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.