Northern Ontario Plant Database

The Genus Salix: Willows have slender branches with alternate leaves, winter buds have a single bud scale. The small, unisexual flowers lack sepals and petals, and are arranged on erect to pendant catkins (aments). Plants are dioecious, with unisexual male and female flowers borne on separate plants. Male flowers usually have 2 stamens, female flowers have a single pistil; both have a basal nectary and are subtended by a scaly bract, often bearing long silky hairs. The fruit is a small narrow conical to ovoid or pear-shaped capsule, with the top portion prolonged into a narrower beak The capsule splits into 2 halves, with each side curving backward to release the woolly seeds.

General: low to medium, deciduous shrub, to 4 m tall; twigs chestnut brown to reddish- or purplish- brown; finely hairy when young, becoming smooth with maturity (glabrate).

Leaves: Alternate, simple, firm, pinnately-veined, petiolate. Leaf blade elliptic to oblanceolate, 2–7 cm long, 1–2.5 cm wide; dark green and lustrous above, paler and glaucous beneath, with short hairs when young, but soon becoming smooth (glabrate); leaf base tapering (cuneate), apex pointed (acute) to blunt (obtuse); margins entire to barely crenate, turned under slightly (revolute). Petiole 2–10 mm long; stipules present, small, ovate, deciduous.

Flowers: Unisexual, male and female catkins (aments) on different shrubs (plants dioecious); catkins sessile, appearing before the leaves. Male (staminate) catkins 1–4 cm long, 1-1.5 cm wide; female (pistillate) catkins 2–6.5 cm long, to 1.8 cm wide. Bracts brown to black, 1–3 mm long, hairy, persistent.

Fruit: A cluster of ovoid capsules, each 5–7 mm long, bearing short hairs.

Habitat and Range: Cool moist habitats; streambanks, meadows, cedar swamps, bogs, and snow beds. The tealeaf willow, a circumboreal species, occurs throughout northern Ontario, but is rarely found south of 48° N (Soper & Heimburger 1982).

Internet Images: Illustrations of Salix planifolia from the Flora of the Canadian Arctic Archipelago. Legend: a) vegetative branch, b) female catkin, c) male flower, d) base of male flower with bract removed, showing the nectary; e) female flower.

Charts comparing traits of the 6 common willows found in the northern Ontario FECs.

	Salix humilis (upland willow)	Salix pedicellaris (bog willow)	Salix petiolaris (slender willow)
leaf shape	oblanceolate to obovate, 3–10 cm long	narrow elliptic-oblong to oblanceolate, 2–5 cm long	linear-lanceolate to oblanceolate, 2–7 cm long
leaf margins	entire to barely crenate, + revolute	entire, slightly revolute	finely serrate, sometimes entire
lower leaf surface	gray-pubescent	glaucous	glaucous
stipules present or absent	present, deciduous	absent	absent
capsule shape & size	ovoid, long beaked, 6–9 mm long	narrow-conical, 6–8 mm long	narrow, long-beaked, 5–7 mm long
capsule pubescent or glabrous	gray-pubescent	glabrous	silvery- pubescent
catkin scales	pale	yellowish	yellowish-brown

	Salix planifolia (tealeaf willow)	Salix discolor (pussy willow)	Salix bebbiana (beaked willow)
leaf shape	elliptic to oblanceolate, 2–7 cm long	elliptic to oblanceolate, 3–10 cm long	elliptic, oblong, oblanceolate, 3–10 cm long
leaf margins	entire to barely crenate, + revolute	crenate to serrate	variable; entire, crenate, or serrate
lower leaf surface	early rusty pubescence, later glaucous	early rusty pubescence, later glaucous	gray-pubescent, often glabrate, then glaucous
stipules present or absent	present, deciduous	present, somewhat persistent	absent or small, deciduous
capsule shape & size	ovoid, short beaked, 5–7 mm long	narrow, long-beaked, 7–12 mm long	narrow, long-beaked, 7–10 mm long
capsule pubescent or glabrous	short-pubescent with fine, silky hairs	short-pubescent with fine, soft hairs	gray-pubescent
catkin scales	brown to black	brown to black	greenish-yellow, red-tipped

Similar Species: For further information on willows, see the webpages on Salix bebbiana (beaked willow), Salix discolor (pussy willow), and Salix humilis (upland willow), from the borealforest.org website, or the Salicaceae family webpage on the Aquatic and Wetland Vascular Plants of the Northern Great Plains website, part of the USGS Northern Prairie Wildlife Research Center network.

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