Species at Risk
Water-pennywort is a tropical plant! The small pocket of it that grows in southwest Nova
Scotia is extremely far north for this plant. This special plant and its habitat are in danger.
What is so special about water-pennywort?
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.
© Parks Canada / James Steeves / 1980
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?
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.
© Parks Canada / Rick Swain / 1980
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.