Illustration from the Illustrated Companion to Gleason and Cronquist's Manual suggests the lobes of the calyx should be hmm...awn-tipped (to borrow from grass terminology). Your plant also only sometimes agrees with the set of photographs via Google Images of Stachys palustris calyx (have a look and see how they tend to be pointier?). But, Gleason and Cronquist also list three varieties (one of which is var. pilosa, seemingly considered its own species now). Does the "similar species" section from this page help in narrowing it down with regard to using the location of hairs on the stems and leaves?
Weird, Stachys pilosa (any varieties at all) isn't in Swink & Wilhelm or Wildflowers of Wisconsin but the USDA site lists it as occurring throughout Illinois and Wisconsin, without any scientific name synonyms. Going by the MN Seasons site you posted, it looks to be S. palustris based on "The hairs on the ridges are distinctly longer but not much stouter than those between the ridges," (rather than equal in length) and because some of the leaves are well wider than S. pilosa var arenicola's "rarely wider than 3/4''" limit.
