Salix pseudomyrsinites is a tall deciduous perennial willow shrub that occurs in boreal to subalpine regions of Denali in floodplains and terraces, boggy sites and shrublands. This species has yellow-brown branches that are pubescent or without hairs. Leaves are elliptic to obovate in shape with finely toothed margins (with glands on teeth), and small stipules. Leaves are green above and below, with white and rusty hairs on the upper surface. Willows are dioecious (separate plants producing either male or female flowers), the flowers highly reduced and borne in catkins. Catkins are on leafy peduncles and develop as the same time as the leaves. Pistils are green in color and hairless. Fruits are capsules that split open by two valves to release many hairy seeds. This species can be differentiated from Salix myrtillifolia by its long, acute and hairy leaves.
Catkins and leaves of Salix pseudomyrsinites appear together in early summer.
S. pseudomyrsinites is dioecious. Flowers are wind and insect pollinated, primarily by bees and wasps. Seeds have attached hairs to allow wind dispersal. As with most willows, this species can also vegetatively reproduce through sprouting.
Salix pseudomyrsinites occurs only in North America, ranging from Alaska east through Canada to Hudson Bay. This species does not occur in the lower 48 states. In Alaska, S. pseudomyrsinites occurs mostly in the interior boreal lowlands. In Denali, S. pseudomyrsinites occurs in widely scattered locations primarily on the north side of the Alaska Range with one occurrence known on the south side of the range near the Tokositna Glacier.