Cedar Lake is a large but shallow glacial lake in central Lake County. The lake is largely pristine due to much of the shores undeveloped and natural. The exception is the residential area on the north side where the water quality has deteriorated as a result of lawns, old septic fields, and road water inflow. The submersed aquatic plants were mostly native species until the Eurasian milfoil appeared and began aggressively growing. The grow quickly to the lake surface and then sideways shading out the native plants. A weevil growing in the native milfoil, a non-aggressive species, gradually began to include the Eurasian milfoil as its food source, and that population crashed. Three years later the milfoil is beginning a resurgence but the weevil population curve is likely to follow in the typical predator-prey cycle and cause the milfoil population decline in a few years.
Cedar lake had four endangered plant species, Potamogeton praelongus, white-stemmed or long neck pondleaf, Potamogeton robinsii, fernleaf, and Potamogeton gramineus, grass-leaved pondweed, now declassified. The endangered Bidens beckii, water marigold, was discovered by Linda Curtis in 1988 during the drought when water levels were low and yellow daisy-like blooms rose above the lake surface, instead of blooming below water. The last specimen recorded in Cedar Lake was in 1887.
The endangered plants are found mostly in the same aquatic beds along with 4 threatened fish species-Notropsis heterodon, blackchin shiner, Notropis herolepis, blacknose shiner, Fundulus diaphanus, banded killifish, and Etheostoma exile, Iowa darter.
Part of the western basin, near the Allendale School, has a state nature preserve, Cedar Lake Bog, which has a lakeside floating bog with endangered plants such as Saracenia purpurea., pitcher plant. Until a fire burned the marsh in 1977, the bog had a stand of Larix laricina, tamarack, such as those at Volo Bog. Only 3 bogs remain in Lake County with tamarack, Volo, Wauconda, and Gavin bog in Grant Forest Preserve. Many more stands existed when settlers came, but were soon used as prime barn support lumber.
copyright © 2014 Linda Curtis, botanist