Introduction
Bunchberry dogwood (Cornus canadensis) is a low-growing, perennial wildflower that is native to cool forest regions across northern North America, Greenland and northeastern Asia. This hardy plant thrives in moist, acidic soils and grows from creeping underground stems called rhizomes.
Bunchberry dogwood is typically found in coniferous or mixed forests, often under the shade of pines, firs and spruces. Its natural range extends from alpine areas to boreal forests across Canada, Alaska, and the northern parts of the continental U.S. such as New England and the upper Midwest.
This plant provides an important food source for wildlife. Its bright red berries are consumed by grouse, pheasants, bears, foxes, and songbirds. Deer and snowshoe hare browse on its leaves and twigs. Insects like bees and butterflies are attracted to its nectar-producing flowers. For these reasons, bunchberry dogwood is considered a keystone understory species in northern forest ecosystems.
Mammals
Bunchberries are an important food source for many mammals in the regions where they grow. Deer, including white-tailed deer and mule deer, browse on bunchberry plants and eat the leaves, stems and fruits (Source 1). Rabbits and hares, such as the eastern cottontail, snowshoe hare, and New England cottontail also feed on bunchberries. Small rodents like chipmunks, mice, and voles are known to eat the fruits and seeds of bunchberries as well (Source 2).
The fruits of bunchberry plants are an important food source for mammals in late summer and early fall when other foods may be scarce. Bunchberries provide nutrients and energy to help mammals prepare for winter. By consuming and dispersing bunchberry seeds, mammals also play a key role in propagating new plants.
Birds
Bunchberries are an excellent food source for many bird species. According to Gardenweb, dogwood berries are favored by grouse, pheasants, and songbirds like juncos, sparrows, and finches.
Grouse, including ruffed grouse and spruce grouse, thrive on the berries of bunchberry dogwood. The high fat content of the berries helps these birds survive the winter. According to the Maine Department of Inland Fisheries and Wildlife, bunchberry is one of the top preferred winter foods for ruffed grouse.
Pheasants also relish the berries of bunchberry dogwood. The shrub’s low growth makes it easy for these ground foraging birds to find and access the nutritious berries. Studies have shown that the presence of bunchberry dogwood in an area increases pheasant abundance and overwinter survival rates.
Many songbirds are attracted to the bright red berries of bunchberry dogwood as well. Juncos, white-throated sparrows, American tree sparrows, and pine grosbeaks often feed on the berries in winter. The high fat and carbohydrate content provides crucial energy for songbirds during the colder months.
Insects
Various insects are drawn to the flowers and fruits of the bunchberry dogwood. Beetles such as long-horn beetles are frequent visitors to the flowers, likely feeding on the nectar and pollen.1 Some moth and butterfly larvae feed on the leaves of bunchberry, including the spring azure butterfly.1 The fruits are eaten by some beetles as well.
Other Wildlife
Bunchberry dogwood is eaten by many kinds of mammals and birds. Bears are especially fond of the berries. Both American black bears and brown bears eat bunchberries (Source). Black bears are omnivores that feed on plants like berries and also hunt small animals. They typically rely on bunchberries as an excellent food source in late summer when the berries ripen.
Foxes such as red foxes and grey foxes also eat the berries (Source). They are omnivores that consume a wide variety of foods including fruits, insects, birds and small mammals.
Seeds Dispersal
Bunchberry dogwood relies on animals to disperse its seeds. The fruits are consumed by many types of mammals and birds [1]. Studies have found bunchberry seeds in the scat of deer, elk, bears, coyotes, foxes, rabbits, and ruffed grouse [2].
The passage through an animal’s digestive system helps break down the seed coat, preparing the seeds for germination. The scat also delivers the seeds to new locations, sometimes miles away from the parent plant. This is an important propagation mechanism that allows bunchberry to colonize new habitats.
Bunchberry seeds that are buried in animal scat have higher germination rates compared to seeds left on top of the soil. The scat provides moisture, nutrients, and protection as the seeds sprout and take root [1].
Some animals may also scatter seeds while handling the fruit without fully ingesting them. Overall, the coevolution between bunchberry and wildlife has produced an effective dispersal strategy.
[1] https://www.fs.usda.gov/database/feis/plants/forb/corcan/all.html
[2] https://www.eopugetsound.org/content/seed-dispersal-15
Medicinal Uses
Bunchberry dogwood has a long history of medicinal use, especially among indigenous peoples in North America. According to the University of Michigan Health, bunchberry was used by the Ojibwe Indians for treatment of urinary tract and kidney issues (source). The leaves and stems were prepared as an herbal tea or medicine. It was taken orally to relieve aches, pains, fevers, and coughs.
Modern research has looked into the potential health benefits of bunchberry dogwood. A 2014 study found that extracts of the plant exhibited antioxidant, anticancer, and anti-inflammatory properties (source). The antioxidants in bunchberry may help protect cells from damage. Some of the plant chemicals have been shown to inhibit growth of certain cancer cells. More research is still needed to fully understand the medicinal benefits.
Today, herbal teas made from the leaves and stems of bunchberry dogwood are still used as a mild painkiller and treatment for fevers, coughs, urinary tract issues, and lung ailments (source). It is generally considered safe when used appropriately. Bunchberry remains an important traditional medicinal plant.
Cultivation
Bunchberry dogwood is relatively easy to grow when provided its preferred growing conditions. It can be grown from seeds or propagated from stem cuttings taken in summer (Source). Seeds should be cold stratified before sowing. Cuttings can be rooted in a moist sand and peat mixture.
Bunchberry thrives in moist, acidic, well-drained soils and partial to full shade. It can tolerate drier soils once established but does best with consistent moisture. It grows well under trees and shrubs. Companion plants include ferns, wild ginger, and other shade-loving perennials (Source).
To grow bunchberry, amend the soil with compost or peat moss to increase acidity and water retention. Mulch around plants to retain moisture. Prune back any damaged foliage after blooming. Divide clumps every 2-3 years to control spread. Watch for pests like aphids, scale, and powdery mildew and treat as needed. Deer tend to avoid this plant (Source).
Threats
Bunchberry dogwood faces several threats to its survival in the wild. Some of the main threats include:
Habitat loss: As with many native wildflowers, habitat destruction is one of the biggest dangers for bunchberry dogwood. Deforestation, development, and fragmentation of forests have destroyed and degraded many of the moist, rich woodland habitats this plant depends on. According to the article “Bunchberry (Cornus canadensis)” on wildadirondacks.org, bunchberry is considered threatened in Ohio due to habitat loss (Source).
Disease: Dogwood anthracnose and powdery mildew are two fungal diseases that can infect bunchberry and other dogwood species. These diseases thrive in warm, humid environments and can damage or kill infected plants. Maintaining habitat diversity and health is key to minimizing disease impact.
Overgrazing: Grazing by deer, livestock, and other animals can quickly degrade bunchberry’s habitat and deplete populations. The dense shade this plant requires may prevent regrowth once its habitat is opened up. Studies show bunchberry abundance is far lower in overgrazed areas compared to protected sites (Source).
Conclusion
Bunchberry dogwood, with its bright white bracts and red berries, is an important source of food and habitat for many types of wildlife. Mammals such as black bears, squirrels, voles, mice, and even deer nibble on the dogwood’s leaves, twigs, and berries. Various bird species like grouse, ptarmigan, sparrows, and waxwings rely on bunchberry berries for sustenance. Bees, butterflies, and other pollinating insects are attracted to the plant’s nectar-producing flowers. Even slugs and snails consume the leaves. Bunchberry dogwood plays a vital role in numerous forest and tundra ecosystems across North America.
Unfortunately, bunchberry dogwood is threatened by habitat loss in many areas. Logging, mining, oil and gas drilling, and other human activities disrupt the plant’s sensitive habitat. Global warming also endangers bunchberry by causing drier conditions and more frequent wildfires in boreal forests. To preserve this important plant, conservation efforts are needed to protect its natural habitat and limit further disruptions. By supporting bunchberry dogwood, we help ensure food and shelter for the many animals that depend on this humble wildflower.