Viburnum trilobum Marshall (redirected from: Viburnum opulus var. americanum)
Family: Adoxaceae
American Cranberrybush,  more...
[Viburnum opulus subsp. trilobum (Marsh.) R.T. Clausen,  more]
Viburnum trilobum image
Michael Huft  
From Flora of Indiana (1940) by Charles C. Deam
Restricted to the lake area where it is found in low woods and on the borders of lakes and streams. It has been reported from Kosciusko, La Porte, Steuben, and Tippecanoe Counties. The Tippecanoe County report is probably based upon a cultivated plant. I found no specimen.


Indiana Coefficient of Conservatism: C = 10

Wetland Indicator Status: FAC

Shrub 1 - 5 m tall Leaves: opposite, stalked, 5 - 10 cm long, as wide or wider, three-lobed, maple-like, base rounded to truncate (cut straight across), lobes pointed, coarsely toothed, palmately veined, slightly hairy on the lower surface. Leaf stalks 1 - 3 cm long, with one to six large glands near the top. Glands stalked, mostly taller than wide, and round-topped. Flowers: in branched clusters (cymes). Cymes terminal, flat-topped, 5 - 10 cm wide, with large sterile flowers surrounding much smaller fertile flowers. Fertile flowers five-lobed, white, to 5 mm wide, tubular, sparsely hairy inside. Stamens five, exserted from the corolla. Filaments white. Anthers tan to yellow. Stigma three-lobed. Sterile flowers marginal, five-lobed, white, 1.5 - 2.5 cm wide, slightly irregular. Fruit: berry-like (drupe), in clusters, bright red, 10 - 15 mm wide, rounded, single-seeded. Twigs: stout, ribbed. Form: rounded.

Similar species: Another variety found in the Chicago Region, var. opulus, differs by having stalkless glands on the leaf stalks that are wider than tall and concave on top. Viburnum acerifolium and V. acerifolium var. ovatum are also similar but have slightly hairy branchlets, purplish black mature drupes, and dots on the leaf undersides.

Flowering: June to July

Habitat and ecology: Rare in rich woods, and has been seen in a bog.

Occurence in the Chicago region: native

Notes: About 200 species of Viburnum occur between North America, Europe and Asia. Many are ornamental shrubs cultivated for their showy flowers, autumn foliage, and attraction to wildlife.

Etymology: Viburnum is the Latin word for the Wayfaring tree. Opulus is the Latin word for a type of Maple. Americanum means "of the Americas" (North or South).

Author: The Morton Arboretum