Water Pennywort, or Hydrocotyle ranunculoides, is considered an invasive species in Wisconsin. This aquatic perennial can be found in shallow, slow moving water and on wet edges and mudflats of lake or pond edges. Water Pennywort prefers full sun to partial shade. The round, deeply lobed leaves reach the water surface from stalks attached to creeping stems. Small, green-white or green-yellow flowers develop in clusters in summer and early fall. This plant reproduces by runner stems and roots, seeds and stem fragments, and can develop large colonies.

The lake operations manager, Charlie Handel of the Delavan Lake Sanitary District, has found that the pennywort spreads quickly in September and closely monitors Delavan Lake during this time.

The WDNR and DLSD need your help. If you see Water Pennywort on your shoreline, or anywhere on Delavan Lake, please contact the Delavan Lake Sanitary District at 262-728-4100 or Heidi Bunk, WDNR, at 262-574-2130. Thank you for your dedication and support of our lake.