Flora of Door County, Wisconsin

[5] In 2006, 60 species of aquatic plants or macrophytic algae were found in Clark Lake and nearby upstream, including spotted pondweed, Potamogeton pulcher, which is endangered in Wisconsin.

[12] A county-wide electronic map of Japanese knotweed, Phragmites, teasel, and wild parsnip infested locations is updated annually.

This forest cover is likely due to the alkaline soil and mostly grows on the Niagara Escarpment along the Green Bay side of the peninsula or near the Lake Michigan shoreline.

[18] The escarpment also features the dry cliff natural community[19] and is home to two rare species of whitlow grass.

Even during times of high water when low-lying plants are inundated, the populations may persist uphill by clonal expansion and spreading their seeds.

Without the changing lake levels the shoreline would be dominated by woody plants or highly competitive and even invasive water-loving species such as cattails, reed canary grass, or purple loosestrife.

Wet meadows like this one thrive when flooding does not occur often enough to allow emergent vegetation to prevail but is still too frequent to allow the establishment of trees and shrubs.