|Publication Type:||Web Article|
|Authors:||Gerdes, LB, Lee, MD|
|Access Date:||11 November 2014|
|Full Text|| |
On June 3, 2009 Michael Lee and I were out botanizing a prominent cliff near the U.S. and Canadian border. It was well understood that we were not the first to explore this feature, for the area's rich botanical history is well told on the pages of botanical journals and well preserved on herbarium sheets at the University of Minnesota and Minnesota-Duluth Herbaria. Early accounts reveal this cliff was first explored by botanists some 120 years ago. For it was in 1889, when F. F. Wood was scrambling high upon these very bluffs when he collected for the first time in Minnesota the small grass like plant, weak arctic sedge (Carex supina ssp. spaniocarpa). Although many determined botanists have revisited this cliff over the years, none have had the pleasure of setting eyes upon Mr. Wood's elusive discovery.
Fred K. Butters and Ernst C. Abbe, two prominent botanists from the University of Minnesota, were among those seeking the rediscovery of this plant in Minnesota. Although their explorations were not able to relocate the weak arctic sedge population that Wood first discovered, on June 25, 1936 they were successful in finding a second occurrence of weak arctic sedge on another cliff 17 miles distant. Over the years, an array of botanists studying our state flora have explored the cliffs of north eastern Minnesota in pursuit of this species. However, neither of the populations have ever been seen again nor had any additional populations of the species been discovered in Minnesota.
Mike Lee taking photo of sedge
And so it was a sunny, Wednesday afternoon in early June, that Mike and I were out and about botanizing Wood's cliff. Botanizing a cliff involves a constant assessment of which vertical chutes warrant climbing and which horizontal shelves and ledges permit closer investigation, an assessment of our safety and determination if our scrambling will cause damage to the cliffs fine, crumbly soils and vegetation. There is no reward or satisfaction to be gained in discovery, if while in its pursuit, one damages or destroys the habitats and treasures being sought.
close up photo of sedge
Weak arctic sedge occupies a broad circumpolar range and typically occupies rocky and sandy substrates in the far arctic regions. Outside of Alaska, the Minnesota records represent the only known occurrences of this species in the United States. Two additional populations, within 3 miles of the extant Minnesota population, are known from Ontario where the species also occurs as isolated cliff populations.
In the Border Lakes region, weak arctic sedge is known to occur in association with north to westerly-facing cliffs of the Rove Formation. Macro-habitats appear to be well drained and sunny to partially sunny. The sedge occurs along the upper rims of cliff tops, in chutes and on shelves of the cliff wall. Associates include: yarrow (Achillea millefolium), columbine (Aquilegia canadensis), tall wormwood (Artemisia campestris), harebell (Campanula rotundifolia), Arabian whitlow grass (Draba arabisans), sticky locoweed (Oxytropis viscida), early saxifrage (Saxifraga virginiensis), rusty woodsia (Woodsia ilvensis), pale bluegrass (Poa glauca), and other fine leaved sedges including northern sedge (Carex deflexa), shaved sedge (Carex rugosperma) and Ross's sedge (Carex rossii).
Carex supina is a perennial herb; 8-30 cm tall. It is long rhizomatous forming loose tufts. Plants are reddish tinged at the base. Leaf blades are 3-15 cm long, 1.0-1.5 mm wide and scabrous margined. The inflorescence typically has 2-5 spikes with the terminal spike being entirely staminate. The pistillate scales are reddish brown with hyaline margins. Perigynia are glossy, dark reddish-brown above and yellowis-green to reddish-brown near the base. The perigynia are 2.5-3.3 mm long and 1.2-2.0 mm wide with beaks 0.4-0.9 mm long. This webpage This link leads to an external site. illustrates these structures in good detail.
border country landscape
Although this arctic species may have persisted at its southern location in Minnesota since the glaciers receded some 10,000 years ago, climate change and other human induced influences (e.g., development, recreation, non-native species) are primary threats to its continued persistence. Although we may not be able to say today what the greater role this species contributes to human kind, we do know it is part of our planet's greater web of life that we are all intricately dependent upon.
It is our hope that in 120 years from now, other botanists will have the privilege of experiencing the weak arctic sedge in Minnesota. To find themselves perched on a small foothold, on the side of a grand cliff and overlook the beauty and serenity of the wilderness landscape of river, lake and forest below.
Butters, F. K. & E.C. Abbe. 1953. A Floristic Study of Cook County, Northeastern Minnesota. Rhodora Vol. 55. The New England Botanical Club. Cambridge, Mass. 21-55, 63-101, 116-154 & 161-201.
Coffin, B. and L. Pfannmuller, eds. 1988. Minnesota's Endangered Flora and Fauna. University of Minnesota Press, Minneapolis. 473 pp.
Gerdes, L. B. 2001. A Contribution to the Flora of the Rove Slate Bedrock Complex Landtype Association, Northern Cook County, Minnesota, USA. (Unpublished Graduate Report - Michigan Technological University, Houghton, MI.) 78pp.
Gleason, H.A. and A.C. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. 2nd ed. New York Botanical Garden. Bronx, NY. 910 pp.