Vaccinium ovalifolium

Oval-leaf huckleberry

Ericaceae

The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Magnoliopsida (dicotyledons). Subclass - Dilleniidae. Order - Ericales. Family - Ericaceae (heath). Genus - Vaccinium L. Species - Vaccinium ovalifolium Sm.

Ecology: Ovalleaf huckleberry grows in cool, moist, submontane to subalpine forests, on open slopes, and at the edges of bogs, meadows, and swamps. It often occurs on elevated microsites in poorly drained areas. Ovalleaf huckleberry is commonly absent from major valley bottoms but does occur on subhydric, colluvial, and morainal sites in smaller valley bottoms. Ovalleaf huckleberry is shade tolerant and can persist in undisturbed forests dominated by species such as western hemlock or white spruce (Picea glauca). It is a common constituent of climax old growth Douglas-fir-western hemlock, Pacific silver fir, and moist western hemlock forests of the Pacific Northwest, and of western hemlock-western redcedar-Sitka spruce forests of southeastern Alaska. Seedlings grow in open, old growth stands or in clearcuts, but often do poorly in dense, immature forests.

Identification

The slender, yellowish-green, glabrous twigs of ovalleaf huckleberry are conspicuously angled. Twigs turn a bright red when exposed to sunlight. Bark of older branches is grayish or grayish-brown. The thin, alternate leaves are entire or have inconspicuously serrate margins. Leaves are oval to elliptical but rounded at the base and tip. Leaves are glabrous and generally light and glaucous below. Ovalleaf huckleberry is crown-forming, clumped, suckering when disturbed, rarely forming extensive colonies, 3-40 dm, not rhizomatous; twigs yellow-green or golden brown, glaucous, usually terete, sometimes somewhat angled, glabrous, sometimes hairy in lines. Leaf blades pale green or glaucous abaxially, slightly darker pale green adaxially, ovate to elliptic, rarely obovate, 25-39 × 16-20 mm, margins entire to obscurely serrate, abaxial surface glabrous, eglandular (sometimes hairy or glandular along midvein), adaxial surface usually glabrous (sometimes hairy and/or glandular). Flowers: calyx pale green or glaucous, lobes vestigial or absent, glabrous; corolla pink, bronze-pink, or greenish white, globose, sometimes urceolate, 5-7 × 4-5 mm, thin, glaucous; filaments glabrous or pilose basally. Berries blue, dull purplish black, or black, sometimes glaucous, 8-10 mm diam. Seeds ca. 1 mm.

Threats

In the WFDP: Ovalleaf huckleberry is subject to herbivory in the WFDP; elk, in particular, may browse ovalleaf huckleberry to a fatal extent. Another key factor affecting mortality of ovalleaf huckleberry in this energy-limited system is suppression.

Fire effects: Basal portions of the stem sometimes survive after aboveground vegetation is damaged by fire. Underground rhizomes are presumably afforded some protection by overlying soil and may survive fires which consume the crown. As with many other species of huckleberry (Vaccinium spp.), plants are most likely to be killed by hot, duff-consuming fires. Seeds of most huckleberries are susceptible to heat and onsite seed is typically eliminated by fire. Plants presumably sprout from the stem base or underground rhizomes after aboveground vegetation is destroyed by fire. Limited seedling establishment may occasionally occur from offsite seed dispersed by birds and mammals.

Reproduction

Seed production and dispersal: Pink, urn-shaped flowers are borne singly in the axils of leaves. Flowers are generally pollinated by long-tongued bees, such as bumblebees. The floral morphology of ovalleaf huckleberry has been examined in detail. Fruit of the ovalleaf huckleberry is a bluish-purple, dark blue, or black berry with a distinct whitish bloom. The relatively large berries are round, spherical, or slightly oblate, and seedy. Each berry contains an average of 26 seeds, but individual berries may contain up to 150 seeds. Evidence suggests that ovalleaf huckleberry is a "seedling banker." Seedlings are capable of surviving in the forest understory until disturbance creates conditions favorable for development. Large numbers of slow-growing seedlings are commonly observed.

Vegetative Reproduction: Ovalleaf huckleberry commonly sprouts from dormant basal buds after repeated browsing or disturbances which damage the crown. Layering, which occurs in the absence of disturbance, has also been reported. Ovalleaf huckleberry is rhizomatous and sprouting of these structures is reportedly the primary means by which colonies expand.

Species Distribution

Citation

USDA Plants Database
USDA, NRCS. 2016. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
Photo credit: Lindsey Koepke, hosted by the USDA-NRCS PLANTS Database

USFS Plant Database
Habeck, R. J. 1992. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.

Flora of North America
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 19+ vols. New York and Oxford.

Burke Museum of Natural History and Culture
Burke Museum. 2016. Vaccinium ovalifolium [Online]. University of Washington.
Photo credit: Wayne C. Weber 2008
Photo credit: G.D. Carr 2009