The Intriguing World of Drosera

Reading about the natural landscape which Indiana has to offer took me on a quest to find out more about a genera of carnivorous plants known as Drosera – also commonly referred to as Sundews. Drosera is the largest group of carnivorous plants having over 194 species.

The Spoonleaf sundew (Drosera intermedia ) is a lovely, small plant with spoon shaped leaves. The tentacles are covered with drops of mucilage waiting for prey to land.

What makes this group interesting is that these plants, as opposed to the well-known family including Venus Fly Traps, do not “capture” insects by reflex or touch, but rather attract insects with a mucilaginous, sweet , and sticky substance which then acts as a kind of fly paper by adhering the insect to the plant. The plant then uses enzymes to kill (within 15 minutes) and dissolve the insect.
The Drosera has very weakly developed roots which are used mainly for anchoring the plant and for absorbing water. Since these plants grow in poor nutrient soil (mainly bogs) the insects are needed to provide essential mineral nutrition which the roots and growing area cannot provide. In fact, if Drosera are grown in wonderfully fertile soil, they will perish.

The Round-leaved sundew (Drosera rotundifolia) is also a tiny plant having enticing mucilage tipped tentacles.

There are two species of Drosera growing in the wild in Indiana at Pinhook Bog which is part of the Indiana Dunes National Lakeshore in LaPorte County. Pinhook Bog covers 580 acres with part of this being a floating mass of sphagnum peat moss, which is where you will find the Drosera. This bog is known as a kettle bog and formed at the end of the Wisconsin Glacial time period. As the glacier retreated, part was left behind which melted and was then sealed with clay. The resulting bog is the perfect environment for these plants having stagnant, acidic and nutrient poor water.

Pinhook bog is only accessible by appointment and may be visited with scheduled guides by park rangers. Tours may be arranged at the Visitor Center of the Indiana Dunes National Lakeshore or by calling (219) 926-7561.

Article submitted by Mary Cusack