Day 353: I spent seven and a half hours on Lake St. Clair yesterday, paddling approximately eleven miles as I conducted a minute examination of almost every log and stump in the water which hosted any type of plant life. I feel I can now say with 95% degree of assurance that the Round-Leaved Sundews occur in only one microenvironment no more than six feet in length and a foot and a half wide. This log is their only home. I believe it was a Douglas fir, and my hypothesis (based on my understanding of mycoheterotrophy and related symbioses) is that a particular fungus affected only this section of the tree. I am led to conjecture that there may have been an intermediary stage where the fungus and a companion algae cooperated as a specific lichen, which then set the stage for the Sundews to colonize.
Drosera rotundifolia is a "carnivorous" plant. Its leaves exude a sticky fluid to attract and trap insects which the plant then breaks down into nutrients by means of enzymes. Five-petalled white flowers emerge in small groups at the tips of stems which rise above the clustered leaves (the brown seed pods are visible in the upper photo). Sundews are moisture-lovers, preferring peaty bogs and decaying wood, but as their name suggests, they grow in sunny areas. These colonies only populate the south side of the log which is exposed to the sun for the better part of the day. Coming on these from the north in early morning light was like paddling toward a field of diamonds...in more ways than one. As a naturalist, finding this species in the wild has been the highlight of my career.
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