Northern Ontario Plant Database

Plant Description

Viburnum cassinoides L.

En: northern wild raisin, witherod, swamphaw
Fr: viorne cassinoïde, bleuets sains, alisier
Oj: bagwaji-zhoominens, zhoominensan

Adoxaceae (Viburnum Family)

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Synonym: Viburnum nudum L. subsp. cassinoides (L.) Torr. & A.Gray

Nomenclatural Notes: Viburnum cassinoides L. is sometimes considered to be a northern upland subspecies (subsp. cassinoides) of an expanded American species, Viburnum nudum L., the naked witherod or smooth witherod. The typical subsp. nudum, known as possumhaw, swamphaw, or southern wild raisin, is restricted to the southeastern U.S. However, the status of this union is still under review, so the NOPD is retaining the name Viburnum cassinoides as the accepted name until the relationship between these two taxa has been fully clarified.

The former Caprifoliaceae (Honeysuckle Family) has been split into two families. The genera Viburnum (viburnum), Sambucus (elderberry), and Adoxa (a European herb), formerly placed in the Caprifoliaceae are now placed in the Adoxaceae (Moschatel Family).

General: An upright deciduous shrub, 1—4 m tall in our area, which makes an excellent addition to a native plant garden, this shrub offers large showy flowers in early to mid summer, colourful fruit that attract birds in late summer, and attractive foliage, dark glossy green in summer and bright orange to red in fall.

Stems/twigs: Northern wild raisin has naked terminal and lateral buds; the long narrow naked buds each have 2 flexible valvate scales that are actually modified leaves, coated with tiny rusty-brown peltate scales. These scales give the buds their rough (scurfy) texture. Young twigs may also be scurfy, but older twigs have smooth (glabrous), greyish bark. Leaf (vegetative) buds are long and narrow, opposite, and may be terminal or lateral. Flower buds, which occur only on terminal branches, are enlarged at the base, with two valvate leaf scales enclosing the embryonic inflorescence.

Leaves: Opposite, simple, pinnately-veined, and firm to leathery (coriaceous); petioles are 0.5—2 cm long and sometimes slightly winged. Leaves of northern wild raisin are very variable in shape; they are most often lanceolate to elliptic, but they may range from narrowly elliptic to obovate. Leaf blades are 2.5—15 cm long by 1.5—6 cm wide; glabrous, dark green, and lustrous above (sometimes with a dull bloom), and slightly paler beneath; leaf bases are tapering (cuneate) to rounded; apices are pointed (acute), sometimes abruptly narrowing to a short acuminate but blunt tip; margins are entire, wavy, or toothed (serrate). Leaves turn orange to red in the autumn.

Flowers: White, bisexual, and numerous; arranged in large, terminal, stalked, flat-topped inflorescences (cymes), 3—10 cm across. All flowers of the inflorescence are fertile, of approximately the same size, and have a slightly disagreeable odour. Individual flowers have a small inconspicuous calyx; a short-tubular 5-lobed corolla; 5 stamens attached to and extending 1—3.5 mm beyond the corolla (exerted); and a single pistil with an inferior ovary. Flowers bloom in early summer.

Fruit: A cluster of ellipsoid to ovoid, berry-like drupes, each 6—9 mm long, with a single seed enclosed in a flat stony pit. Young fruit are greenish-white, soon turn bright pink, then mature in mid to late summer to bluish-black, the skin changes from smooth to wrinkled at maturity, often with a heavy bluish-grey (glaucous) bloom. Fruit are edible, with sweet pulp, and ripen in mid to late summer. In late autumn, the decaying leaves and fallen fruit give off a distinctive sweetish odour.

Habitat and Range: Moist to wet open woods, thickets, forest borders, and swamp margins throughout the mixedwood and southern Boreal Forest regions, extending from Newfoundland through northeastern Ontario, as well as southern and eastern Ontario. In the Algoma District, northern wild raisin is common up to the Batchawana Bay area, but is rarely found as far north as Wawa.

Similar Species: The similar nannyberry (Viburnum lentago L.) overlaps the range of northern wild raisin only in southern and eastern Ontario; nannyberry also occurs near the Minnesota border in northwestern Ontario and southwest of Lake Nipissing in northeastern Ontario. It can be recognized by its larger size (to 6 m tall), leaves with finely serrate (serrulate) leaf margins and flat winged petioles, larger inflorescences of sweet-smelling flowers, and its scurfy greyish-brown winter buds. Nannyberry prefers wet habitats in basic soils.