In 1933 I found a small colony of this species in the tamarack border of the east side of Cogg Lake, Lagrange County. It grew in the shade in sphagnum around the base of a small tamarack with Menyanthes, Sarracenia, and Vaccinium macrocarpon. It was at maximum anthesis on July 15. This species was reported in 1878 from Jefferson County by Barnes, but no data accompanied the report. There is a specimen in the herbarium of Indiana University which was collected by Young in Jefferson County, September, 1875. In 1935 it was again found in Jefferson County by Miss Edna Banta. It was growing in shallow soil on a high ledge of rock on the border of a seeping spring on the north slope of Big Creek, a mile south of Lancaster.
Stems very slender, creeping; lvs orbicular to broadly ovate, 1-5 cm wide, shallowly 6-10-lobed; umbels sessile or subsessile, 2-7-fld, the pedicels under 1 mm; fr 1.5 mm wide, the dorsal surface acute, the dorsal and lateral ribs acute. Moist low ground; Nf. and Que. to Wis., s. to N.C., W.Va., and Ind. June-Sept.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.