This weekend I spent some time in an abandoned cranberry bog – although it has not been actively cultivated for years, it still produces a decent amount of cranberries. With no one to weed the bog, however, the plant diversity has increased substantially. There are now sapling trees (e.g., gray birch, pitch pine), ladies’ tresses orchids (Spiranthes sp.), and a variety of aster and goldenrod species. With all this additional growth, and without a functional water control system, rather than skimming the floating berries off the surface of a flooded bog, harvesting cranberries from a bog like this requires hand picking. (Pro tip: Bring something soft and waterproof to kneel on.)

At first I tried honing my search image to find the ripe cranberries amidst the tangled vegetation. But with so much time looking closely at the ground, I started to notice a whole new miniature world, with an amazing variety of plants, mosses, and lichens all less than an inch or two tall. The highlight for me was finding spoon-leaved sundews (Drosera intermedia) among these tiny treasures. The largest was perhaps two inches in diameter, but I saw many that were smaller than a cranberry. 

Sundews, like the more commonly known Venus flytrap, are carnivorous plants. The “spoon”-shaped leaves of this sundew species are covered with glandular hairs, which exude a dew-like drop of sticky fluid. Insects are attracted to the droplets, but become entrapped in the sticky fluid when they land on the plant. The struggling action, as the insect tries to free itself, triggers movement (actually extremely rapid cell growth) in the leaf, which extends to fold over the insect in about a minute, more securely trapping it. This reaction is only triggered by repeated movement; a single touch or a falling leaf will not initiate this response. Once the insect is trapped, the leaf secretes two substances: 1) an anesthetic that seems to stupefy the prey, and 2) digestive enzymes that dissolve the insect’s internal organs (the exoskeleton is left largely undigested). The dissolved nutrients are then absorbed by the leaf and transported to the plant’s vascular system. The entire process may take a week or more. The spoon-leaved sundew is common in bogs and wet sandy areas. Its ability to trap and consume insects gives it an advantage over other plants in nitrogen-poor soils, since its “diet” can be supplemented by its insect catch. 

Luckily, humans are much too big to be a meal for a sundew, but for a small insect, it’s a different story.