Bicknell's geranium is named for New York amateur botanist and ornithologist Eugene Pintard Bicknell (1859-1925). A true geranium, it belongs to the genus Geranium, unlike garden-variety "geraniums" in the genus Pelargonium. The wild geranium (Geranium maculatum) is a closely related species native to Minnesota's deciduous woodlands.
Usually biennial, occasionally annual, its five-lobed green leaves form a cushion, about 1 foot across and 6 inches high the first year. It has several erect stems 1- to 2-feet tall with small leaves and a handful of small (half-inch) magenta flowers at the tip the second year. Its bright green leaves and pink flowers often stand out against a background of black charcoal, since the species blooms profusely after forest fires. It blooms from June to September.
Habitat and Range
Bicknell's geranium occurs across the boreal forest from Newfoundland to British Columbia, including northern Minnesota. There are scattered occurrences in the mountains of Appalachia and the western United States, and the plant is on state endangered lists in Illinois, Indiana, Ohio, and Pennsylvania. Although a few Bicknell's geraniums can always be found on rocky outcrops throughout Minnesota's Arrowhead region, its populations here typically irrupt after big forest fires.
This fire species has a buried seed strategy. Its tiny seeds have little food value and do not attract seed-eating insects or rodents. Therefore, its seeds stay buried in soil until exposed to sunlight, such as when a fire burns away leaf litter. Pin cherry, red raspberry, and other species with buried seed strategies show up alongside Bicknell's geranium after fires in northern Minnesota.
Bicknell's geraniums cover the ground within a year after intense fires, thus preventing soil erosion and holding onto nutrients that might otherwise leach out of the ecosystem. In effect, the plant is nature's bandage that helps the landscape begin the healing process after a major disturbance kills the forest. The population reseeds itself and persists for a few years after fire until larger vegetation, such as tree saplings, shade it out, at which point the seeds simply fall on the soil, get covered by leaf litter, and wait until the next forest fire.
Lee E. Frelich, director University of Minnesota Center for Hardwood Ecology