The Natural History of Vaccinium parvifolium Smith, the Red Huckleberry

Freya G. Holm

The Evergreen State College, Olympia, Washington 98505

May 2004

Vaccinium parvifolium Smith, commonly known as red huckleberry or red whortleberry, is in the Ericaceae (the heath family), which is part of the order Ericales. While the majority of the Ericaceae are distributed in the tropics, taxonomically diverse ericoids are also widely dispersed throughout North America. Within the tribe Vaccinieae, the genus Vaccinium includes approximately 450 species of shrubs and lianas (Powell and Kron 2002) and is divided into 33 sections (Sleumer 1941). Results from cladistic analyses suggest that Vaccinium is polyphyletic and that the majority of sections within the genus are not monophyletic (Kron et al. 1999; Kron et al. 2002).

Figure 1. Branches of mature V. parvifolium. The Evergreen State College, May 2004.

Vaccinium parvifolium inhabits forests throughout the western coast of North America, including Alaska, British Columbia, Washington, Idaho, Oregon, and California. It generally grows in coastal regions and west of the Cascades and Sierra Nevada. With a wide geographic range, V. parvifolium is also widely distributed at elevations ranging from sea level to 5,000 feet (Tirmenstein 1990).

Preferred habitat is in coniferous submontane to subalpine forests, often at edges and in canopy gaps. Dominant tree species associated with V. parvifolium in mixed evergreen forests include Pinus jeffreyi, P. lambertiana, Libocedrus decurrens, Quercus chrysolepis, Lithocarpus densiflorus, and Arbutus menziesia. Coastal coniferous forests dominated by Picea sitchensis, Tsuga heterophylla, Abies magnifica, Alnus rubra, and Chamaecyparis lawsoniana are also commonly inhabited by V. parvifolium (Tirmenstein 1990). Preferred soil conditions are loamy and acidic with significant decaying organic matter. While soils tend to be nitrogen-poor, they exhibit a wide range of nutrient conditions, from very low to high availability. Vaccinium parvifolium generally grows on rotting logs, snags, or stumps as well as on the ground and it is a dominant component of stump vegetation (Kennedy and Quinn 2001).

Vaccinium parvifolium is an erect deciduous shrub that grows up to four meters tall. It has sharply angled, slender green branches that become grayish-brown as they mature. The growth form is generally trailing for the first four to five years, after which the shrub assumes a more upright habit (Tirmenstein 1990). The growth habit is similar to that of V. alaskaense (Alaska blueberry) and thus V. parvifolium can be mistaken for the more northern species (Szczawinski 1962).

Figure 2. Mature V. parvifolium growth habit.

The leaves are simple, alternate, and up to three centimeters in length. Corresponding to the changes in growth habit, two distinct leaf types exist. The immature leaf form persists for the first 3-4 years of the plant’s life with the mature form following in succession. Developing plants feature dark green, finely serrate, evergreen leaves. In contrast, mature V. parvifolium leaves are bright green, entire and mainly deciduous (Tirmenstein 1990).

The flowers of V. parvifolium are greenish-yellow to pinkish and up to 5mm in length, bell-shaped, pentamerous, and occurring singly in leaf axils. Corolla lobes alternate with sepals. Ten stamens occur in two whorls of five each. Ovaries are epigynous. Anthers feature short, pore-bearing tubes and prominent awns or tubules, which are direct apical continuations of the anther lobes. Each anther contains two awns in North American species of Vaccinium. Pollen is shed in tetrahedral tetrads and is released through awns (Palser 1961).

 Fruits of the red huckleberry are globose, occurring as bright red berries up to 10mm in diameter, with a somewhat sour taste. Seed production is abundant. Each berry contains approximately 20 smooth, reddish seeds that are 1-1.2mm in diameter. The fruits themselves are high in carotene, manganese, and energy content (Tirmenstein 1990).  

Vaccinium parvifolium can utilize two methods of reproduction: seeds and vegetative means. Seed production may constitute the more common form of regeneration (Vander Kloet 1988), a characteristic not shared by the majority of western huckleberries (Martin 1979). According to a study conducted on V. parvifolium in British Columbia, up to 25 percent of the seeds of an average shrub ultimately germinated (Vander Kloet 1988). Stem, branch or rhizome sprouting is generally employed as a response to disturbances such as heavy herbivore browsing, fire damage, or human removal, but this response also occurs in the absence of disturbance (Halpern 1989).

Seeds are dispersed by a number of vertebrates, mainly by birds and small mammals. Banana slugs may also play important roles in seed dispersal (Gervais et al. 1996).

Vaccinium parvifolium is able to survive many disturbances and thus plays an important role in forest succession. The shrub reacts differently to the effects of logging, burning, and other modifications, depending on bioregion and specific growing conditions (Tirmenstein 1990). For instance, in Picea sitchensis-Tsuga heterophylla dominated forests of southeast Alaska, V. parvifolium was found to emerge during the first three years after logging (Alaback 1984). However, severely burned sites may not allow regeneration of V. parvifolium, in part because seeds are heat-susceptible and rhizomes may be destroyed by acute fire (Tirmenstein 1990).

Numerous vertebrates and a few invertebrates consume fruits, young shoots, or leaves. A variety of birds eat V. parvifolium berries including thrushes, catbirds, band-tailed pigeons, bluebirds, ptarmigans, towhees, ring-necked pheasants, as well as spruce, ruffled, blue, and sharp-tailed grouse. Mammals such as Sitka black-tailed deer, elk, mountain goats, mountain beavers, deer mice, white-footed mice, raccoons, red foxes, squirrels, skunks, gray foxes, grizzly bears, pika and black bears also commonly eat berries. Sitka black-tailed deer and elk have been found to rely heavily on browsing V. parvifolium branches as a primary food source during the maritime winter season, according to a study conducted on animal populations on Etolin Island, Alaska (Kirchhoff and Larsen 1998). Small mammals also heavily browse red huckleberry. The mountain beaver of Oregon’s Coast Range depends on the berries as a major food source. Banana slugs have also been studied as red huckleberry frugivores (Gervais et al. 1996).

Indigenous human uses of red huckleberry have been numerous and varied. All First Nations within the range of the plant ate fresh huckleberries. Some coastal tribes, such as the Sechelt, often ate berries accompanied by oil or animal fat and mixed with berries of other species, such as salal. The berries of V. parvifolium were also preserved for winter usage by a smoke drying process, then mashing and drying into cakes. The berry juice has been consumed as a mouthwash and appetite stimulant. To cure sore throats and inflamed gums, some indigenous groups gargled a decoction containing the leaves and bark, in addition to using the leaves for tea (Pojar and MacKinnon 1994). While several species of Vaccinium are commercially produced and marketed (e.g. V. macrocarpon, V. angustifolium, V. myrtilloides), V. parvifolium is mainly used on a local level to make jams, jellies, and desserts (Tirmenstein 1990).

Few scientific studies have been conducted on Vaccinium spp. in natural ecosystems (Grelet et. al 2001; Kennedy and Quinn 2001; Powell and Kron 2002). Some areas of future research could include studies of V. parvifolium seed dispersal by invertebrates, the relationships of major clades within Vaccinium (Powell and Kron 2002), and the type of mycorrhizal association formed by Vaccinium spp. in forest ecosystems.

References

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Gervais, J. A., A. Traveset, and M. F. Willson. 1996. The potential for seed dispersal by the banana slug (Ariolimax columbianus). The American Midland Naturalist 140:103-110.

Halpern, C. B. 1989. Early successional patterns of forest species: interactions of life history traits and disturbance. Ecology 70:704-720.

Kennedy, P. G. and T. Quinn. 2001. Understory plant establishment on old-growth stumps and the forest floor in western Washington. Forest Ecology and Management 154:193-200.

Kirchhoff, M. D. and D. N. Larsen. 1998. Dietary overlaps between native Sitka black-tailed deer and introduced elk in southeast Alaska. Journal of Wildlife Management 62:236-242.

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Pojar, J. and A. MacKinnon. 1994. Plants of the Pacific Northwest Coast: Washington, Oregon, British Columbia & Alaska. Vancouver, BC: Lone Pine Publishing.

Powell, E. A. and K. A. Kron. 2002. Hawaiian blueberries and their relatives-A phylogenetic analysis of Vaccinium sections Macropelma, Myrtillus, and Hemimyrtillus (Ericaceae). Systematic Botany 27:768-779.

Sleumer, H. 1941. Vaccinioidee-Studien. Botanische Jahrbücher 71:375-510.

Szczawinski, A. F. 1962. The Heather Family (Ericaceae) of British Columbia. Victoria: British Columbia Provincial Museum.

Tirmenstein, Debra A. 1990. Vaccinium parvifolium. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). 

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