Features: The Flooded Jellyskin (Leptogium rivulare) is a leaf-like lichen that grows at the base of trees growing around vernal ponds that fill with meltwater in spring, then dry up in summer. The lichens, which are bluish-grey when dry, swell up and become translucent when they are submerged (hence the name “jellyskin”). Lichens are compound organisms consisting of a fungus co-existing with an algae or bacteria. Flooded Jellyskin lichen have a fungus “skin” (thallus) packed with cyanobacteria (formerly known as blue-green algae) that can conduct photosynthesis and produce sugars, which are then used by both the fungus part and the bacteria part of the lichen.

Lichens grow slowly – perhaps one millimetre per year. Indivdual lichens grow to about 6 cm, but lichens cluster and can form larger encrustations half a metre across trees.

Status: Threatened Provincially and Nationally

Range: The Flooded Jellyskin is a northern hemisphere species, found in eastern North American and western Europe. It is known historically from herbarium specimens from Illinois and Vermont, but recent localities are restricted to Canada. In Canada, it has a curious disjunct distribution: present at a site near Flin Flon, Manitoba, and at three sites around Ottawa in eastern Ontario. Range Maps

Threats: Flooded Jellyskin has always been rare throughout its range. While it has an extremely restricted range, there are likely thousands of individuals present at ponds in Ontario. Ponds are being threatened by recreational use and housing development. One of the main tree species around the vernal pools that the lichens live on is Black Ash, which is threatened by a recent invader, the Emerald Ash Borer.

Protection: The Flooded Jellyskin is protected from harm under Ontario's Endangered Species Act, 2007. In Ontario, one site is on public land owned by the National Capital Commission, where it receives additional protection. The remaining sites are on private land.

Text Sources: Lee 2004

Last Modified Date: October 2008