Blackhaw Viburnum
Viburnum prunifolium
Honeysuckle family (Caprifoliaceae)

Description: This is a branched woody shrub or small tree up to 15' tall. The young bark of small branches is gray and slightly rough, while the old bark of the trunk or larger branches is grey and rough with flat-topped plates. The opposite leaves are up to 3" long and 1" across; they are ovate or ovate-obovate, glabrous on both their lower and upper sides, and finely serrated along their margins. The slender petioles are up to 1" long and reddish. The buds of these leaves are short.

Cymes of flowers about 3-5" across develop from the axils of the leaves; each cyme is much branched, but sessile at the base. Each flower is about " across; it has 5 white petals that are well-rounded and longer than the sepals. There are 5 long stamens with slender white filaments and yellow anthers, and a small pistil at the center of the flower that is cream-colored at the base. The blooming period occurs from mid- to late spring. The flowers have a strong and pleasant fragrance; they are produced at about the same time as the leaves. Each flower is replaced by a fleshy ovoid drupe about 1/3" (8 mm.) long; this drupe becomes blue-black at maturity, sometimes with a whitish bloom. Inside each drupe, there is a single stone (a seed with a hard coat) that is flat on one side and convex on the other. The drupes are sweet and edible, although somewhat thin-fleshed because of their stones. The root system consists of a branching woody taproot.

Cultivation: The preference is light shade to partial sun, mesic to dry conditions, and soil that is loamy, clayish-loamy, sandy-loamy, or somewhat rocky. This shrub can assume somewhat irregular shapes, depending on lighting conditions.

Range & Habitat: The native Blackhaw Viburnum is occasional to locally common in most areas of Illinois; it is less common or absent in parts of NW and southern Illinois. Habitats include rich mesic woodlands, upland woodlands, thinly wooded bluffs, rocky wooded slopes, limestone glades, woodland borders, and areas along woodland paths. This species is found in deciduous woodlands, particularly where oaks are dominant. It can decline in abundance when a woodland is invaded by non-native Honeysuckle shrubs, such as Lonicera maackii (Amur Honeysuckle) and Lonicera tartarica (Tartarian Honeysuckle).

Faunal Associations: The nectar and pollen of the flowers attract primarily small bees and various flies. Among the bees, these flower visitors include cuckoo bees (Nomada spp.), mason bees, Halictid bees, and Andrenid bees. Among the flies, these flower visitors include Syrphid flies, dance flies (Empididae), bee flies (Bombylius spp.), Tachinid flies, blow flies (Calliphoridae), and Muscid flies. Other flower visitors include butterflies, skippers, hummingbird moths, and ants, which seek nectar. The caterpillars of the butterfly Celastrina argiolus (Spring/Summer Azure) feed on the flowers and buds of Viburnums, while later caterpillar instars of the butterfly Euphydryas phaeton (Baltimore) occasionally feed on their leaves, after migrating from the original host plant (e.g., Aureolaria spp.). Several moth caterpillars also feed on Viburnums (see Moth Table). An introduced beetle, Pyrrhalta viburni (Viburnum Leaf Beetle), feeds on the leaves. Among vertebrate animals, the drupes are occasionally eaten by birds, primarily during the fall migration (see Bird Table); they are also eaten by the Eastern Chipmunk, tree squirrels (Red, Gray, & Fox), and the White-Footed Mouse. White-Tailed Deer browse on the twigs and leaves.

Photographic Location: An upland wooded area along a path at Busey Woods in Urbana, Illinois.

Comments: This is an attractive shrub, particularly during the spring when the flowers bloom. It can be used in landscaping and other horticultural purposes. Blackhaw Viburnum is fairly easy to identify. The most similar species is Viburnum lentago (Nannyberry), which has similar white flowers and blue-black drupes. However, the leaves of Nannyberry have longer tips than those of Blackhaw Viburnum. Other Viburnum spp. have leaves that are smooth or coarsely serrated, whereas the leaves of Blackhaw Viburnum are finely serrated. Some species in this genus, for example Viburnum dentatum (Arrow-Wood), have straight branches and flowers with an unpleasant fragrance. The branches of Blackhaw Viburnum are more crooked and the fragrance of its flowers is sweet and pleasant.