What is water-pennywort?

Water-pennywort growing in the water

Water-pennywort is a small perennial plant with round, scalloped-edged leaves. Growing primarily on sandy or gravely lakeshores, it has slender stems that creep along the ground and leaves that either float in the water or stand upright. The leaves are a rich green, except for their pale green centre, where the stems attach. It occasionally produces small clusters of white flowers on a single stalk, called an umbel, in mid to late summer.

Water-pennywort thrives in lakeshore habitats where few other plants can tolerate the force of the wind and the waves, the fluctuating water levels, and the gouging winter ice. In Kejimkujik National Park and National Historic Site of Canada, the plant grows in thick colonies in the shallow water of sandy or gravely beaches. Although easily overlooked, this special plant is a significant feature along the edge of Kejimkujik Lake.

Where is water-pennywort found?

Water-pennywort only occurs in two locations in all of Canada, and both of these are in southwestern Nova Scotia . One of the province's rarest plants , it grows on part of the shoreline of Wilson's Lake in Yarmouth County and is scattered along Kejimkujik Lake and George Lake within Kejimkujik National Park and National Historic Site of Canada. These two locations represent the northern limit of this plant's distribution.

Water-pennywort is common in the southern part of its range, occurring as far south as Mexico and Florida, and stretching up along the eastern seaboard of North America as far north as Massachusetts. The Canadian populations are extremely isolated and rare.

What is the status of water-pennywort?

Water-pennywort growing on the lakeshore

Water-pennywort is listed as threatened by COSEWIC and is protected under federal Law by the Species at Risk Act. Water-pennywort is also protected under provincial legislation with the Nova Scotia Endangered Species Act under which it is listed as endangered. These listings differ since the levels of government list species under their own set of criteria based on priorities within their jurisdictions.

What is so special about water-pennywort?

Water-pennywort growing up out of the water

Water-pennywort is a tropical plant by origin! It is part of a unique group of species called the Atlantic coastal plain flora. These plants are usually found much further south, from the Gulf of Mexico to New England.

There are 66 species of these wildflowers, herbs, and plants in southwestern Nova Scotia; almost 50 of them grow within Kejimkujik National Park and National Historic Site. Twenty of these coastal plain plants are not found elsewhere in Canada. These plants are at the northern limit of their range, isolated from the closest populations to the south. Water-pennywort is the rarest of these special plants.

Why is water-pennywort in danger?

Within the boundaries of Kejimkujik, the main threat to the water-pennywort is trampling. This plant is quite small, difficult to see, and grows right on the beach where there is potential for people to accidentally step on it as they swim, walk, or beach their canoes.

The leaves of the water-pennywort float on top of the water when the lake levels are high. When the water levels drop over the course of the summer, the leaves stand upright. Some people say that the leaves look like opened umbrellas; others say that their silhouettes look like lollipops.

There are only two small populations of water-pennywort in Canada , which is why it is at risk. Research has indicated that in Canada this plant does not produce seeds. This means that all reproduction is asexual, as the plant grows up from its creeping roots. This may limit its genetic diversity.

Water-pennywort is also very susceptible to climactic changes such as temperature and lake water levels. The populations in Nova Scotia are healthy and stable, and the stands in Kejimkujik have shown an increase in recent dry years. However, with so few populations, many factors still put the species in danger.

Outside of Kejimkujik, the habitat of water-pennywort is threatened. Like other Atlantic coastal plain flora, the lakeshore habitats of water-pennywort are being damaged or eliminated by cottage development and the plants are being trampled by all-terrain vehicle use.

What is Parks Canada doing to help the water-pennywort?

Recovery actions

A park warden ropes off water-pennywort habitat to protect it.

All water-pennywort habitat within Kejimkujik receives the highest level of protection. Within these areas of special protection, no development or recreational activities may occur.

Where water-pennywort grows near beaches and campgrounds, its habitat is fenced off and signs are posted to inform visitors of the importance of these sensitive areas. Trails along the lakeshore are designed so that visitors can see the lakeshore habitats and plants without trampling them. The National Recovery and Conservation Action Plan of Hydrocotyle umbellata (water-pennywort) is currently being developed for this species that outlines long term objectives for future recovery actions.


Research and monitoring within Kejimkujik allow for a better understanding of this plant's biology, and how Parks Canada can protect it. In cooperation with the Université de Moncton and the Centre of Geographic Sciences in Lawrencetown, Nova Scotia, a number of field studies are being conducted to determine the present and historic distribution of water-pennywort. These studies will also help us understand the genetic diversity and special habitat requirements of this plant as well as its response to environmental change. This information will be important for protecting water-pennywort and its habitat in the future.

Public education

A park interpreter gives a guided walk on water-pennywort.

Kejimkujik also offers a variety of information to help people learn about water-pennywort, other coastal plain flora, and species at risk in southwest Nova Scotia . This includes interpretive signs, videos, Web sites, brochures, and more. Programs are also delivered to local schools to better their understanding of species at risk and rare plants.

Working with partners

The Atlantic Coastal Plain Flora Recovery Team is completing a recovery and action plan for water-pennywort and is recommending actions to improve the conservation, recovery and management of this species. This plan will itemize and define protection strategies for water-pennywort both within and beyond the Park boundaries.

Parks Canada is a member of the recovery team, which consists of a variety of representatives, including:

Panels and rope protect the habitat of the water-pennywort
  • Nova Scotia Department of Natural Resources
  • Nova Scotia Department of Environment and Labour
  • Nova Scotia Nature Trust
  • Nova Scotia Museum of Natural History
  • Acadia University
  • Université de Moncton
  • St. Mary's University
  • Centre of Geographic Studies
  • Atlantic Canada Conservation Data Centre
  • local museums
  • private landowners
  • interested public

How can I help?

If you are visiting Kejimkujik National Park and National Historic Site of Canada:

  • You must respect the roped-off, closed areas of the lakeshore near the campground.
  • Stay on designated paths to avoid trampling vegetation.
  • When you explore by water, please avoid canoeing into thick vegetation.
  • When visiting the Park, participate in interpretive programs and activities to learn more about this special plant and how you can help. With this information, you can let other people know of the plight of the water-pennywort.

If you are outside Kejimkujik:

  • If you or your family has a cottage by a lake, make a concerted effort to favour natural vegetation along the shore, and try not to alter the shoreline or disturb the plants that are in the shallow water.
  • If you use an all-terrain vehicle, do not drive along the shorelines of lakes, which are sensitive habitats for this special vegetation.