Drosera rotundifolia

round-leaved sundew

by Leila Duncan

Round-leaved sundews are one of several species of carnivorous plants in the family Droseraceae. They are notable both for their delicate beauty and clever strategy. Unfortunately, these tiny plants are often overlooked by visitors to Garden in the Woods. With 3-6 by 2-4 mm leaves on narrow stalks, usually growing in rosettes, this is unsurprising but unfortunate.

Sundews, along with other bog plants, are faced with nitrogen deficient soil. They have turned to insects as a source of this key nutrient and the trap they set would look right at home in a modern art glass gallery. Rounded green pads on narrow stalks radiate thin, red hairs in all directions. A sticky substance filled with digestive enzymes is secreted from the tip of these hairs, topping them with clear droplets that sparkle in the sun. When an insect comes in contact with this substance it becomes stuck and only entangles itself further by struggling. The sticky pad curves or is pulled by the struggle around an insect’s body which is broken down by the secretion resembling dew such that nutrients may be absorbed directly through the sundews leaf.

The rosette sends up a spindly stalk that produces diminutive flowers with pink to white petals, but they are outshined by the sundews colorful leaves. Extracts of Drosera rotundifolia have been shown to be anti-spasmodic as well as anti-inflammatory and extracts of this plant are used in homeopathic medicine to treat whooping cough.

These striking plants prefer moist acidic conditions. Look for them in the bog habitat at Garden in the Woods among pitcher plants and sphagnum moss.