USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

Aquatic and Wetland Vascular Plants of the Northern Great Plains

21. Salicaceae, the Willow Family

2. Salix L. -- Willow

7. Salix exigua Nutt. -- Sandbar willow, coyote willow

Colonial, rhizomatous shrub to 4 m tall, often forming dense thickets; twigs light yellow to orange, glabrous; branchlets erect, yellow to orange, glabrous. Leaves yellowish-green above, the same or paler beneath, initially pubescent and soon glabrous (rarely persistently silvery-pubescent), or persistently gray-pubescent, linear-lanceolate, slowly tapered to an acute tip, acuminate at the base, 4-10 cm long, 2-10 mm wide, remotely and irregularly dentate; petioles glandless, 1-5 mm long; stipules minute or absent. Catkins emerging after the leaves, borne on leafy branchlets 0.5-10 cm long, these often branched; female catkins 1.5-8 cm long; bracts deciduous, yellowish; stamens 2. Capsules narrowly ovoid, 4-8 mm long, glabrous (although pubescent when immature); stipes 0.5-1 mm long. Flowering May--early Jun, fruiting Jun--early Jul. Shores, stream banks, alluvial bars, ditches and other wet places; often a pioneer species in the stabilization of sand bars and other alluvium; common; (N.B. and Que. to AK and B.C., s to VA, TN, LA, TX, CO and MT). S. interior Rowlee.

Two subspecies of S. exigua occur within the northern Great Plains. The prevalent form by far is subsp. interior (Rowlee) Cronq., sandbar willow, with the leaves usually glabrous at maturity, although rarely silvery-pubescent; capsules 5-8 mm long and distinctly stipitate so that the female catkins appear rather loose and elongate. This subspecies occurs throughout our area.

Subsp. exigua, coyote willow, enters our range from the west, occurring sparingly in w SD, w NE, e MT and e WY. It differs from subsp. interior in having the leaves persistently gray-pubescent, at least beneath; capsules 3-5(6) mm long, sessile or nearly so, the female catkins mostly dense and short. This form is characteristic of western North America.
gif-Salix exigua subsp.

Salix exigua subsp. interior, showing a closeup of a twig with female catkins. Photo by James R. Johnson.
GIF- Distribution Map

Map key

Previous Species -- Salix eriocephala Michx. -- Diamond willow, Missouri willow
Return to Family -- Salicaceae - The Willow Family
Next Species -- Salix fragilis L. -- Crack-willow, brittle willow

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:47:05 EST
Sioux Falls, SD [sdww55]