Viola septentrionalis Greene [Upper Midwest variant]
Common names:
None.
Synonyms:
None.
Description:
Acaulescent rosulate perennials from thick rhizome, ≤ 29 cm tall; most features same as V. septentrionalis sensu stricto, but foliage uniformly densely hirsute; calyx commonly pubescent, densely ciliate nearly or fully to apex (hairs often long); lowest sepals consistently broadly ovate-lanceolate to ovate, obtuse to rounded; seeds **–** × **–** mm, **, with small weak darker streaks or spots; 2n=54.
Ecology:
Broad habitat type is somewhat similar to Viola septentrionalis sensu stricto in terms of sandy or gravelly or rocky soils in open dry-mesic or mesic northern forests, but consistently on or around outcropping basaltic (presumably somewhat acidic) exposures.
Distribution:
Upper Midwest and adjacent Ontario, thus far well represented in the Thunder Bay District southward into ne. and e. MN, then sporadically down the e. edge of IA. Somewhat overlapping the Driftless Area.
Rarity:
None.
Phenology:
Presumably same as Viola septentrionalis sensu stricto.
Affinities:
This species belongs to the Acaulescent Blue Violet lineage, sect. Nosphinium W.Becker, subsect. Boreali-Americanae (W.Becker) Gil-ad, in the Sororia species group.
Hybrids:
None.
Comments:
Fernald (1950), Alexander (1963), and Scoggan (1978) reported V. septentrionalis from Michigan and westward in the Midwest. Specimens from Minnesota could certainly be the basis for this variant; however, I have examined all major herbarium collections in Wisconsin and have not yet confirmed the presence of V. septentrionalis in that state. The collections in Michigan must be reexamined, as my early studies (Ballard 1995) included V. septentrionalis in a broadly defined V. sororia. Russell (1965) mapped V. septentrionalis in the western Great Lakes region but inexplicably placed records in southern Michigana and southern Wisconsin, not at all biogeographically sensible for this generally boreal or high-elevation montane species. These have been dismissed as V. sororia. This variant is not dramatically divergent from V. septentrionalis sensu stricto elsewhere across its range, but specimens are quite uniform in foliage and peduncle indument, a broader ciliate sepals with obtuse to rounded apex, and are distinctive in seeds with weak but noticeable small dark streaks and spots. Plants and populations elsewhere in the eastern range of the species are quite variable in the same features, and seeds are uniformly unspotted. Since the specimens represent a southward extension of an otherwise boreal Canadian range for the species in the Great Lakes region and central Canada, the plants deserve further scrutiny. The variant should be sought elsewhere in the Driftless Area and southward along the river valley bordering Iowa and Illinois.
Literature Cited:
Alexander, E. J. 1963. Violaceae. In Gleason, H. A., The new Britton and Brown illustrated flora of the northeastern United States and adjacent Canada. Hafner Publishing Co., Inc., New York, NY. 552-567.
Ballard Jr., H. E. 1995 ["1994"]. Violets of Michigan. Michigan Botanist 33: 131-199.
Brainerd, E. 1921b. Violets of North America. Vermont Agricultural Experiment Station Bulletin 224: 1-172.
Fernald, M. L. 1950. Violaceae. In Gray's Manual of Botany, 8th ed. American Book Company, New York, NY. 1022-1042.
Russell, N. H. 1965. Violets (Viola) of the central and eastern United States: An introductory survey. Sida 2: 1-113.
Scoggan, H. J. 1978. Violaceae. In Flora of Canada, Part 3–Dicotyledoneae (Saururaceae to Violaceae). National Museums of Canada. Ottawa, Canada. 1103-1115.
Seeds from herbarium specimen: Newfoundland, Valley of Exploits River, Bishop Falls, Boggy thickets, 28-29 Jul 1911, M. L. Fernald & K. M. Wiegand 5878 (VT)
Map by Biota of North America Program