Kingdom: Plantae – Plants

Phylum: Magnoliophyta – Flowering plants

Class: Magnoliopsida – Dicotyledons

Family: Salicaceae - willows

Common Name: Scouler’s willow

Species Code: SASC

Origin: Native to streamsides, moist meadows, clearings in forests, and moist upland sites over much of western North America from Alaska to California and east to Saskatchewan and New Mexico.

Rare: no

Form: dioecious shrub or tree, 2-12 m tall, branches erect; twigs yellowish to reddish brown, sparsely to densely pilose, becoming glabrate with age.

Duration: perennial

Longevity: long-lived

Habitat Type: wetland, riparian, shrub thickets, forest

Wetland Indicator Status: FAC

Leaves: alternate, petiole frequently pilosulose but sometimes glabrous; blade broadly lanceolate to ovate or obovate, 3.5-8 cm long and 1-3.5 cm wide, commonly hairy when young, becoming glabrate and dark green above (except the midrib often remaining hairy), glaucous and rusty-tomentose to densely white-woolly below, margins generally entire, sometimes toothed; stipules leaf-like, 3-13 mm long, longer on vigorous young shoots.

Mature height: 6-40 feet

Flowers: borne in unisexual aments (catkins) from lateral buds on the old wood, precocious or rarely coetaneous, sessile or on short peduncles; scales black, persistent, long hairy; staminate aments 2-4 cm long, glabrous or sparsely hairy at the base, with 2 stamens; pistillate catkins 2.5-6 cm long, styles 0.2-0.6 mm long, ovary silky.

Flower color: yellow

Bloom: early spring

Fruit: capsule, narrow with a long beak, densely white pilosulose, 5-8 mm long; seeds with a tuft of long hairs.

Characteristics:
Salix scouleriana generally inhabits drier sites than other willow species and is often found on upland sites.
Reproduces sexually by seed. Vegetative reproduction is also common, as stems detached from the plant root readily in moist soil.
Salix is a difficult genus taxonomically because the plants are dioecious, vegetative and sometimes even floral characteristics are variable, multiple ploidy levels and aneuploidy may be present, and some species may even be apomictic (Hitchcock et al 1969).
6,500,000 seeds/lb (Hassell et al 1996, USDA NRCS PLANTS Database 2007).
Fruit is a capsule.
2n=76,114 (Baldwin et al 2004). About 114 (University of British Columbia 2003).
Salix flowers are mostly insect pollinated but some wind pollination also occurs (Hitchcock et al 1969). Many different pollinators visit the flowers of Salix spp. (Mosquin 1971).
Plants are dioecious and xenogamous.
Willows in general are browsed by livestock and big game animals and eaten by beaver. Thickets provide cover for birds and mammals. Some birds and small mammals feed on the leaves and buds.
Native peoples used various species of willows for basketry, mats, construction, tools, cordage, and medicine.
Catkins are usually precocious but occasionally coetaneous.
Seeds are dispersed by wind and water.
Rocky Mountain elk browse the twigs in winter (Kufeld 1973).
Salix scouleriana generally inhabits drier sites than other willow species and is often found on upland sites.
The poplar and willow borer, Cryptorhynchus lapathi, an introduced weevil from Eurasia, attacks many species of willow and poplar. Larva bore into the stem and weaken them, causing breakage or death (Broberg 1999, Broberg et al 2005). Cytospora canker is a disease caused by the fungus Cytospora chrysosperma. Symptoms are an orange liquid oozing from the stem, and orange colored dead bark (Jacobi 2006). Cankers usually appear in the upper portion of a shoot and move downward. Shoots under moisture stress are the most susceptible to infection (Bloomberg 1962). The pathogen tends to infect plants which are stressed (Kepley & Jacobi 2000). Cytospora canker enters the stem through existing wounds to the bark. Willows (Salix spp.) and poplars (Populus spp.) are most susceptible.

Sun requirement: full sun to partial shade

Soil moisture: mesic

Precipitation: 11-40 inches (USDA NRCS PLANTS Database 2008).

Fire: Increases after fire. Resprouts from from root crowns and recolonizes from wind-borne seed (Anderson 2001).

Hazards: Despite legends from ancient time in Middle Earth regarding the capture of Meriadoc Brandybuck and Peregrin Took by a species of willow, there are no reports of any such activity in our local willows.

Sowing time: spring

Transplant time: spring

Stratification: none required

Seed harvest: difficult, timing is very important

Seed cleaning: difficult

Planting duration: long

Seed insect problem: none noted

Seed shatter: high

Seed size: small

Seed harvest date: early spring

Seed comments: seed is windborne

Propagation:
3 protocols in the Native Plant Network
University of Kentucky
Glacier National Park, Montana
Los Lunas, New Mexico Plant Materials Center

Other Propagation Information:
Grow from cuttings or transplants in spring. Difficult to establish from direct seeding (Kingery 2003).
Willows root readily from hardwood cuttings and germinate easily from seed, but seed is short-lived and must be kept moist during germination. Seed propagated containerized material is preferable for restoration planting because it maintains genetic diversity and assures establishment. Reproduces sexually by seed. Vegetative reproduction is also common, as stems detached from the plant root readily in moist soil.

References:
Amlin, N.M. and S.B. Rood. 2002.Comparative tolerances of riparian willows and cottonwoods to water-table decline. Wetlands 22:338-346.

Anderson, Michelle D. 2001. Salix scouleriana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2009, March 7].

Argus, George W. 2004. A Guide to the Identification of Salix (willows) in Alaska, the Yukon Territory, and Adjacent Regions. Online at http://aknhp.uaa.alaska.edu/willow/pdfs/GuideSalixAK-YT11May05.pdf Accessed 12/10/06.

Bloomberg, W.J. 1962. Cytospora Canker of Poplars: Factors Influencing the Development of the Disease. Canadian Journal of Botany 40:1271-1280.

Broberg C.L., J.H. Borden, & L.M. Humble. 2002. Distribution and abundance of Cryptorhynchus lapathi on Salix spp. in British Columbia. Canadian Journal of Forest Research 32(3):561-568.

Broberg, Cynthia L., John H. Borden, and Regine Gries. 2005. Olfactory and Feeding Preferences of Cryptorhynchus lapathi L. (Coleoptera: Curculionidae) Among Hybrid Clones and Natural Poplars. Environmental Entomology 34:1606-1613.

Darris, Dale C., and Scott M. Lambert. 1993. Native Willow Varieties for the Pacific Northwest. USDA, Soil Conservation Service, Corvallis Plant Materials Center. Corvallis, OR.

Dawes, Denny. 2003. Using a Shop Vacuum to Clean Salicaceae Seeds. Native Plant Journal. 4(2): 140.

Dreesen, David R. 2003. Propagation Protocol for Container Willows in the Southwestern US Using Seeds. Native Plant Journal. 4(2): 118-124.

Dumroese, R. Kasten, David L Wenny, and Susan J. Morrison. 2003. Propagation Protocol for Container Willows and Poplars Using Mini-cuttings. Native Plant Journal 4(2):137-139.

Jacobi, W.R. 2006. Cytospora Canker. Colorado State University Extension bulletin no. 2.937. Online at http://www.ext.colostate.edu/pubs/garden/02937.html Accessed 10/12/06.

Kepley, J.B. and W.R. Jacobi. 2000. Pathogenicity of Cytospora Fungi on Six Harwood Species. Journal of Arboriculture 26:326-332.

Heinze, Donald H. 1994. Willows of Montana. Riparian Tech. Bull. No 2. US Dept. of the Interior, BLM Montana State Office. Billings, MT.

Landis, Thomas D., David R. Dreesen, R. Kasten Dumroese. 2003. Sex and the Single Salix: Considerations for Riparian Restoration. Native Plant Journal. 4(2): 110-117.

Martens, Ellen, and James A. Young. 1992. Seed Germination Data for Yellow Willow at a Nevada Riparian Site. p 142-144 in: Proceedings – Symposium on Ecology and Management of Riparian Shrub Communities. USDA forest Service Intermountain Research Station Gen. Tech Report INT-289.

Mather, Tim. 2003. Propagation protocol for Bare root Willows in Ontario. Native Plant Journal. 4(2): 132-136.

McCreary, Douglas D. and Jerry Tecklin. 2000. Homemade Dibble Facilitates Planting Willow and Cottonwood Cuttings. Native Plants Journal 1(1):59-60.

Mosquin T. 1971 Competition for pollinators as a stimulus for the evolution of flowering time. Oikos 22. (3): 398-402.

Stannard, Mark, and Haley Guenther. 1999. Rooting Characteristics of Black Cottonwood and Pacific Willow. Plant Materials Tech Note 29. USDA, NRCS. Spokane, WA.

Uchytil, Ronald J. 1991. Salix drummondiana. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [accessed 2009, January 29].

Visalli, Dana. 2006. The Wind and the Willows: Why the Genus Salix is Worth a Second Look. Douglasia 30(1):10-13.

Zasada, John C., D.A. Douglas, and W. Buechler. undated. Salix L. willow. In: Bonner, Franklin T., and Rebecca G. Nisley (eds.). Woody Plant Seed Manual. USDA Forest Service. Available online at http://www.nsl.fs.fed.us/wpsm/ Accessed 1/29/09.

Links: Plant Profile from the USDA PLANTS Database
Species account from the Fire Effects Information System
Species information from the University of Washington Herbarium