Salix richardsonii is a large willow with leafy, toothed stipules at the base of the leaf and persistent dead stipules on the branches. This thicket-forming shrub grows up to 4 m tall and occurs in floodplains and terraces, meadows and subalpine slopes across Denali. Branches are reddish-brown, pubescent and often covered with old dried stipules giving it a shaggy look. Leaves are elliptic, hairy and shiny above, less hairy and pale beneath. Leaf margins are either entire or glandularserrate. Willows are dioecious (that is, individual plants produce either male or female flowers only) and the flowers are highly reduced and borne in catkins specialized for wind pollination. Catkins develop well before the leaves and are borne directly on the stem. Pistils are sessile and hairless. Fruits are capsules which split open to release plumed seeds. Capsules are hairless. The presence of leafy stipules with glandular teeth that are persistent for multiple years is a key to identifying Salix richardsonii, along with the fuzzy, white-hairy young twigs.
Catkins of Salix richardsonii develop before the leaves and appear during or right after snow melt.
S. richardsonii is dioecious and insect and wind pollinated. Seeds have attached hairs to aid in wind dissemination.
Collett (2004) documented a variety of insects that utilize S. richardsonii including gall-formers such as: Rabdophaga spp., Pontia sp. and Eriophyiid mites, and leaf skeletonizers from the Chyrsomelid family of beetles. This species is the host plant for larvae of various butterflies including: the Dingy Fritillary Boloria improba, the Purple Bog Fritillary Boloria titania, and the Giant Sulfur Colias gigantea (Scott 1986).
Native Americans made a tea from boiled bark of S. richardsonii for sore throats and tuberculosis, while flexible shoots were woven into baskets and furniture. S. richardsonii is an important browse species for moose.
Salix richardsonii is an amphi-Beringian species ranging from Siberia eastward through Alaska and across northern Canada to Baffin Island and south into British Columbia. In Alaska, this species occurs statewide except is absent or rare on the southern Alaska Peninsula and Aleutians, and southeastern panhandle. In Denali, S. richardsonii is common on both sides of the Alaska Range, forming thickets in swales and drainages.
Salix richardsonii is a common thicket-forming willow that is found in the park at elevations from 73 m to 1486 with an average site elevation of 753 m. It is most commonly found on moderately steep slopes with an average site slope angle of 10 degrees. This species slightly prefers north-facing to south-facing slopes.