Species distinguishing characteristics:
- Red-stemmed shrub with opposite branches and opposite leaves
- Oval leaves with 5–7 prominent, curving veins
- Flat-topped clusters of tiny, white flowers at stem tips
- Bluish-white berries
- Often grows in large patches in moist soils
- Woody plants, usually shrubs and trees, with opposite or whorled leaves
- Leaves are simple, lack stipules, and often have prominent parallel veins
- 4 white, petal-like bracts surround clusters of tiny flowers at the stem tips
- Flowers have 4–5 small sepals (sometimes lacking), a similar number of petals, and 4–5 stamens (pollen organs)
- Fruits are clusters of 2-celled (occasionally 1- or 4-celled) berries with one stony seed per cell
Deciduous perennial shrub, 1–6 m tall, with many erect or spreading stems. Prostrate lower branches often touch the ground and root like stolons into new plants. Often grows in large patches.
Leaves and stems:
Few to many stems with opposite branches and opposite, stalked leaves, 4–12 cm long and about 2/3 as wide. Leaves are oval with pointed tips and entire margins. The upper side of the leaf is green, and the underside is paler. Leaves have 5–7 prominent, sunken parallel veins that curve around the midvein and converge at the leaf tips. Gently pulling the leaf apart width-wise reveals that the veins have white threads of latex inside. Leaves turn reddish-maroon in autumn.
Young stems are smooth and bright red to reddish-purplish, sometimes tinged with green. Older stems are dull red to greyish-green.
Many tiny, white to greenish-white flowers in dense, flat-topped to slightly hemispheric, branched flower clusters, 2–4 cm wide, at stem tips. Flowers have 4 tiny sepals, 4 white petals, 2–4 mm long, 4 stamens (pollen organs), and 1 style (tubular portion of a female organ), 1–3 mm long. Red-osier dogwood flowers lack the big showy bracts typical of other dogwood flowers.
Clusters of round, bluish-white berries that each contain a single flattened, stony seed. Each juicy berry, 7–9 mm in diameter, can be smooth or slightly hairy.
Moist to wet stream banks, river banks, lake shores, swamps, thickets, forests, and avalanche slopes at low- to mid-elevations.
The stems and winter buds provide valuable winter forage for deer (Cervidae spp.), moose (Alces alces), elk (Cervus elaphus), and snowshoe hare (Lepus americanus); these species eat the forage in such high quantity that it often colors their urine a reddish tinge. Red-osier dogwood often suffers from overbrowsing in winter range. Grizzly bears (Ursus arctos), black bears (Ursus americanus), ruffed grouse (Bonasa umbellus) and many other species of birds eat the berries. The berries are somewhat palatable - some people believe the whiter berries are less bitter than the bluer berries - but both can cause vomiting and mild symptoms of toxicity when consumed in large quantities. Some tribes value the berries and mixed them with sweeter berries (such as serviceberries (Amelanchier alnifolia) or chokecherries (Prunus virginiana)), and sometimes sugar, to make a dish called “sweet and sour.” Some tribes also ate the seeds separated from the flesh as a snack.
Many tribes mixed the scraped and dried green, inner bark of red-osier dogwood with tobacco to make smoking mixtures. It can be slightly narcotic, or sleep-inducing. The inner bark has a mild, aspirin-like effect and may be boiled for use as a pain-relieving poultice to treat sores and swelling, or ingested as a tea to treat fevers and liver ailments. An infusion of the mildly astringent roots was used to alleviate diarrhea and as a facial wash or steam for oily skin.
The genus name Cornus means "horn" in Latin and refers to the hardness of the wood. Bows, arrow shafts, digging sticks, pipe stems, drumsticks, and tipi stakes and pins were crafted out of the straight stem wood. The strong, Y-shaped crotches of branches are useful as slingshots, cooking racks, and kettle hangers. The common name red-osier is derived from a French word used to describe long shoots (such as willow) that are used for basket making and wicker. Young stems are useful for basket weaving and less flexible, older stems are prized for basket rims. The stems were also used as skewers and frames for racks to dry berries and salmon, and imparted a nice flavor to the food. The colorful outer bark was also used decoratively. The Blackfoot people made gambling wheels out of beaver teeth that were split in half, tied into a circle, and covered with dogwood bark.