Red-osier dogwood is a relatively common shrub along stream courses, easily recognized by bright red stems and opposite leaves whose veins tend to swoop upwards. When the leaves are carefully torn, fibers connecting the veins are another diagnostic feature. The red stems provide lovely winter color, with the pigment possibly providing a level of protection against the sun after the leaves have fallen. “Osier” is an Old English name for several species of willow used in basketry; the name has been applied in North America to superficially similar species of dogwood.
The nomenclature of red-osier dogwood is convoluted, in part because of uncertainty concerning exactly which of the many possible variants is the one that Linnaeus’s name Cornus sericea should belong to. As a result, the correct name for our local variant of red-osier dogwood has flip-flopped between Cornus sericea (as used in Flora of North America and Intermountain Flora) and C. stolonifera (as used in the 2018 treatment in Flora of the Pacific Northwest). The former name is adopted here, based on the lectotypification cited in Flora of North America. Furthermore, although subspecies or variety have often been recognized under either name, these are now more likely to be treated as separate species (e.g., Cornus occidentalis, which doesn’t occur in this part of Idaho) or not considered sufficiently distinct for taxonomic recognition at any rank. As an additional complication, the genus Cornus is itself sometimes divided into several genera, in which case red-osier dogwood would be treated as Swida.
Red-osier dogwood is among the easiest of our local shrubs to identify, even in winter. However, be alert for bloodtwig dogwood (Cornus sanguinea), non-native look-alike that is now established along the Boise River in central Boise (e.g., next to Boise State University). Identification clues are described under the latter species.
Bernice Bjornson had this this to say about red-osier dogwood in 1946: “Early in the spring drive along a river or creek and enjoy the bright red of the bark of Idaho’s native dogwood. [The shrub] stands transplanting well and can often be found among the lilacs, hydrangeas, syringas, and other shrubs around southern Idaho homes.”