Flower:

Male and female flowers are on separate plants (dioecious) in spike-like clusters (catkins) at the tips of very short branchlets or from buds along 1 year old branches, emerging with or just before the leaves. Male catkins are ½ to 2 inches long, the flowers densely to somewhat loosely packed, each flower with 2 yellow-tipped stamens. Female catkins are ¾ to 2½ inches long, the flowers crowded or somewhat loosely arranged on the spike, bulbous at the base with a long beak, hairless, and on slender stalks 1.2 to 2.8 mm (less than 1/8 inch) long. At the base of each male and female flower stalk is a tiny, dark brown or bi-color scale-like bract covered in long, white hairs.

Leaves and stems:

Leaves are alternate, 1 to 6 inches long, to 1+ inch wide, 2.3 to 8 times as long as wide, narrowly oblong to elliptic, mostly widest at or just above the middle, pointed at the tip, wedge-shaped to somewhat rounded at the base, finely toothed around the edges with rounded teeth. The upper surface is medium to dark green, the lower surface paler green.

At the base of the leaf stalk is a pair of large, leaf-like appendages (stipules) that are rounded or pointed at the tip, up to ½ inch long. New leaves are sparsely to moderately covered in white hairs on one or both surfaces and are typically red-tinged, becoming hairless and green with age. The main veins are mostly curved upward from the midvein with minor veins more obscure. New branchlets are short-hairy and green to yellowish, turning red and becoming hairless the second year.

Stems are multiple from a compact crown, have smooth to slightly rough gray bark and can reach 8+ inches diameter.

Fruit:

The spike elongates some as fruit matures, the fruit becoming more loosely arranged than the flowers.

Fruit is a capsule 3.5 to 7 mm long, yellowish to reddish when mature, hairless, pear-shaped, inflated at the base with a long beak. The capsule splits into two halves when mature, releasing the cottony seed.

Notes:

There are over 20 species of Willows in Minnesota; Missouri River Willow is one of several common species and is a large, multi-stemmed shrub, found in a variety of moist to wet places including lake and pond margins, swamps, wet meadows and wet ditches, often with other Willow species. It is one of the earliest spring bloomers and an important food source for emerging bees. It is recognized by the early bloom period; large, persistent stipules; first year twigs green and hairy turning red the second year; toothed leaves, young leaves typically reddish and at least somewhat hairy becoming hairless; hairless capsules 3.5 to 7 mm long on stalks less than 3 mm long; male flowers have 2 stamens. Both male and female flowers are subtended by a tiny, dark brown or bi-color bract covered in long, white hairs. Leaf shape is somewhat variable, from elliptic to narrowly oblong or very narrowly elliptic. Note that the stipules start becoming apparent as fruit develops.

Missouri River Willow flowers and fruits about the same time as Pussy Willow (Salix discolor), and its leaves may resemble those of Meadow Willow (Salix petiolaris); both of these have hairy capsules and lack the large stipules. The leaves may also be mistaken for Black Willow (Salix nigra), which also lacks the large stipules and often has small glands at the tip of the leaf stalk where it meets the blade, plus it is a small to midsize tree rather than a multi-stemmed shrub. But it may most closely resemble Yellow Willow (Salix famelica), which was once considered a var of S. eriocephala; it has yellow(ish) second-year twigs rather than red, early leaves lack the large stipules, and capsules have at least some hairs at the base.

Missouri River Willow sometimes goes by common name Heart-leaved Willow, which is a misnomer since the leaf bases are rarely, if ever, heart-shaped. There have been several vars noted for S. eriocephala at different times, which are now apparently recognized as separate species (e.g. var. watsonii = S. lutea, var. famelica = S. famelica). S. eriocephala also hybridizes with several other Minnesota willows; hybrids with S. famelica have been recorded from 9 counties from Winona to Becker, and once with S. petiolaris in McLeod County.