Symphytum officinale (Common Comfrey)
|Also known as:||Knitbone|
|Habitat:||part shade, sun; average to moist, disturbed soil; roadsides, waste areas, fields|
|Bloom season:||May - August|
|Plant height:||24 to 42 inches|
|Wetland Indicator Status:||none|
|MN county distribution (click map to enlarge):|
|National distribution (click map to enlarge):|
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Racemes of ½-inch hanging, funnel-shaped, pink to purplish flowers on slender stalks, arising from leaf axils and the end of branching stems in the upper part of the plant. Clusters are initially tightly coiled, unwinding as it matures. The bell-like flower has 5 shallow but distinct lobes that are strongly curled back; the tubular throat is about as long as the bell. Inside the tube are 5 stamens and a long, white style that barely protrudes beyond the mouth of the bell. The calyx behind the flower has 5 lobes that are lance shaped and shorter than the floral tube. Calyx and flower stalks are both covered in spreading, bristly hairs.
Leaves and stems:
Leaves are basal, alternate on the lower stem and may be opposite in the upper plant, 2 to 10 inches long, ¾ to 4 inches wide, lance-elliptic to egg-shaped, toothless, bristly hairy, tapering to a pointed tip and narrowing at the base to a winged stalk. Basal leaves are largest and long-stalked, becoming smaller and shorter-stalked as they ascend the stem with the upper leaves stalkless or nearly so.
The winged leaf stalks extend down the stem (decurrent). Stems are erect to ascending, multiple from the base and forming dense clumps, branched in the upper plant, and densely covered in bristly hairs.
Fruit is a cluster of 4 nutlets that mature to shiny brownish-black. The elongated white style projects from the center while it ripens.
Common Comfrey is another garden escapee that, while not widespread, is likely under-reported in Minnesota. It is similar in many respects to the native Northern Bluebells (Mertensia paniculata), which is most easily distinguished by its blue flower color, appressed hairs on the calyx, forest and forest edge habitat, and range limited to our northeast counties, where Common Comfrey is much more densely clump-forming, has pink to purplish flowers, spreading hairs on the calyx, is more likely found in sunnier, disturbed soils such as roadsides and vacant lots, and may be found anywhere in the state, especially in areas where it is sold as nursery stock. While it may not produce abundant seed, it spreads vegetatively, resprouting from root fragments. Common Comfrey has a long history of medicinal use but also has toxic properties that can cause liver damage and even death.
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Where to buy native seed and plants ↓
- Common Comfrey plant
- Common Comfrey plants
- a clump of Common Comfrey
- garden grown Common Comfrey
- escaped Common Comfrey
- long, persistent style
Photos by K. Chayka taken at Savanna Portage State Park, Aikin County. Other photos courtesy Peter M. Dziuk.
Have you seen this plant in Minnesota, or have any other comments about it?