Northern Ontario Plant Database

Plant Description

Ilex verticillata (L.) A.Gray

En: winterberry, black alder
Fr: houx verticillé
Oj: biboonmiin, awenisiibag, animoshi-min

Aquifoliaceae (Holly Family)

Click on thumbnail to see larger image.

General: A deciduous, many-branched, erect shrub, 1-4 m tall.

Stems/twigs: Bark is dark brown to blackish and smooth (glabrous). Young twigs are greenish-brown, older twigs are slightly ridged, reddish- to grayish-brown, smooth, with scattered lenticels; the alternate buds have several, overlapping, reddish brown bud scales. Terminal and lateral buds are present; terminal buds are ovoid and blunt; lateral buds are smaller, broad and somewhat flat, blunt, and clustered near the end of the twig; leaf scars are semi-circular, occur on slightly raised bases, and have a single bundle scar.

Leaves: Alternate, simple, pinnately-veined; petioles are about 1 cm long and somewhat hairy. Leaf blades are elliptic to obovate, 3-9 cm long by 1-4 cm wide, smooth (glabrous), and often rugose, with veins impressed slightly, giving the leaves a rough appearance. Upper leaf surfaces are dark green and dull to shiny, lower surfaces are paler and smooth to slightly hairy along the veins. Leaf bases are tapering (cuneate); leaf apices may be blunt to pointed (acute), often narrowing abruptly to a narrow point (acuminate); margins are sharply toothed (serrate). Leaves remain green until they fall in mid-autumn.

Flowers: Primarily unisexual, with male and female flowers on different shrubs (plants dioecious); occasional bisexual flowers may occur. Flowers are small, axillary, solitary or in few-flowered clusters, each borne on very short stalks (peduncles). Flowers have a calyx of 4—9 green lobes and 4—8 (usually 7) oblong to rounded, white petals; male (staminate) flowers have 4—9 stamens; female (pistillate) flowers have a single pistil with a superior ovary topped by a broad, sessile stigma. Flowers bloom in May, as the leaves are expanding.

Fruit: Smooth, globose, orange-red to bright red, berry-like drupes, about 6 mm in diameter, each with 3—5 small pits; fruits are borne on short stalks (peduncles). Fruits mature in late summer and persist on the twigs well into winter.

Habitat and Range: Shrubby marshes, shorelines, edges of peatlands, and wet ditches. Winterberry is a temperate eastern North American species that occurs commonly in eastern and southern Ontario; in northern Ontario, it extends north to about 48°N (Soper & Heimburger 1982).

Similar species: Shrubs of Aronia melanocarpa (Michx.) Elliott (black chokeberry) may be confused with small winterberry shrubs. Both species have obovate, shiny leaves, but black chokeberry can be distinguished by the small, glandular hairs found along the midrib on the upper leaf surface and the glandular-tipped marginal teeth. Also, black chokeberry has sharply pointed, red buds and purplish-black fruit.