Northern Prairie Wildlife Research Center
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.
Previous Species -- Salix eriocephala Michx. --
Diamond willow, Missouri willow
Return to Family -- Salicaceae - The
Next Species -- Salix fragilis L. -- Crack-willow,