Flower:

Male and female flowers are on separate plants (dioecious) in spike-like clusters (catkins) at the tips of short branchlets or from buds along 1 year old branches, emerging before the leaves. Male catkins are short cylindric, ¾ to 1½ inches long, the flowers densely packed, each flower with 2 stamens, the tips (anthers) initially red to purple, turning yellow. Female catkins are ¾ to 2½ inches long, the flowers moderately to densely crowded on the spike, bulbous at the base with a long beak, covered in short silky hairs, and on slender stalks .5 to 1.1 mm long. At the base of each male and female flower stalk is a tiny, dark brown to blackish, scale-like bract densely covered in long, straight hairs.

Leaves and stems:

Leaves are alternate, 1½ to 4¾ inches long, to ¾ inch wide, 4.5 to 11 times as long as wide, narrowly elliptic to lance-linear, widest near or below the middle, pointed at the tip, wedge-shaped to somewhat rounded at the base, toothless, the edges often rolled under (revolute) especially near the base. The upper surface is dark green, slightly glossy, hairless to sparsely hairy, with a strong network of indented veins; the lower surface is silvery-white from a dense covering of silky, straight to somewhat tangled hairs.

Leaf-like appendages at the base of the leaf stalk (stipules) are mostly absent or obscure. New leaves are yellowish to reddish and densely white-hairy, sometimes with a few rusty-colored hairs. New branchlets are yellowish and mostly hairless, becoming dark reddish to purplish-brown the second year, often with a whitish waxy coating.

Stems are usually multiple with smooth to rough gray bark. Branches are brittle at the base and may take root if broken off.

Fruit:

The spike elongates some as fruit matures, the fruit becoming more loosely arranged than the flowers. Fruit is a capsule 3.5 to 6.5 mm long, yellowish when mature, covered in short, silky hairs, inflated at the base with a long, straight to slightly curved beak. The capsule splits into two halves when mature, releasing the cottony seed

Notes:

There are over 20 species of Willows in Minnesota; Satiny Willow is a large shrub or occasionally a small tree, primarily found on sandy or rocky lake shores and stream and river banks. It is very rare in Minnesota, where it reaches the southern fringe of its range in the arrowhead region of the state. According to the DNR, the first record is from 1886 at Lake Vermilion in St. Louis County and only 4 known locations existed when it was listed as Special Concern in 1996. Targeted biological surveys have since found only 8 more populations, most of which are along an 8-mile stretch of the Cloquet River. Its habitat is at risk from human activities and natural disasters; a single weather event or development project could conceivably destroy a large portion of this species' presence in the state. It was elevated to Threatened in 2013. It is currently listed as Endangered in Wisconsin.

It is a fairly distinct species, recognized by the hairless twigs usually having a whitish waxy bloom; narrow leaves that are toothless, typically rolled under along the edges (revolute), and have silky, mostly straight, white hairs on the underside; fruit 3.5 to 6.5 mm long covered in short, silky hairs. It is not likely to be found in swamps, marshes or bogs. The leaves are very similar to Sage-leaved Willow (Salix candida), which is a low shrub usually under 3 feet tall with hairy stems, prominent stipules, and leaves and fruits that are woolly-hairy (tangled, matted hairs). Satiny Willow is known to hybridize with several other willows but none have been recorded in Minnesota.