Flower:

Solitary yellow flower on a slender naked stem rising out of the water or moss. Flowers are ¼ to ½ inch across with 5 to 8 (frequently 6), narrow, lance-elliptic petals and 3 broad green sepals as long as or shorter than the petals, with a scattering of yellow stamens around the green styles in the center.

Leaves and stems:

Leaves are basal, round to oval in outline, emerging on a slender stalk and cleft into 3 rounded segments that may have one or more additional shallow lobes. The blade is typically wider than long, ½ to 1 inch long and 2/3 to 1 2/3 inch wide, the surfaces waxy smooth and the edges with wide, rounded teeth or notches. The stem is prostrate along the ground or within the muck or moss layer, rooting at the nodes and creating large colonies.

Fruit:

The center expands into a hemispheric seed head up to 3/8 inch across. The seeds are smooth, the beak curved with a hook at the tip.

Notes:

Lapland Buttercup, sometimes known as Coptidium lapponicum, is a cold hardy circumpolar species native up into the high arctic, whose southern range boundary barely pushes onto northern portions of Minnesota, Wisconsin, Michigan and Maine, all of which list it as rare. Its aversion to heat keeps it hidden away in rich forested northern swamps that are continuously serviced by cold groundwater. According to the DNR, it was listed as a Special Concern species in Minnesota in 1984; it is also currently listed as Endangered in Wisconsin. Its most immediate threat would be changes in local hydrology that would disrupt its cold water supply. Long term, a progressive shift towards warmer temperatures due to climate change will inevitably push its southern range boundary further into Canada. At first glance, the leaves may resemble those of Goldthread (Coptis trifolia), which has 3 separate leaflets rather than a single leaf lobed in 3 parts.