Deb Babcock: Curious flora that feed on fauna
January 6, 2013
Some people say we gardeners are consumed by our plants. I don't think they mean it literally, but there is a group of bizarre plants that obtain nourishment from consuming animals … not necessarily gardeners.
While most are found in exotic places, a couple of these carnivorous plants grow naturally in Colorado.
Carnivorous plants are a curious species of flora that have adapted to environments that lack certain nutrients in the soil. Instead, these horticultural hunters obtain nutrients by digesting small insects and other animals.
Some are jug-shaped, such as pitcher plants, which fill with water and drown the bugs that drop by in search of nectar. Some have a sticky substance on their leaves that captures and anesthetizes insects. And some have touch-sensitive triggers that cause a leaf to wrap around a visiting insect or a jaw-like leaf that clamps tightly shut. Enzymes secreted onto the trapped bugs cause the tissue to breakdown into a nutritious liquid that then is absorbed by the plant.
While the famous Venus Flytrap (Dionaea Muscipula) is the most well-known of this grouping, more than 600 species and subspecies of carnivorous plants have been identified. Spikes on the hinged leaves of the Venus Flytrap snap shut when an insect lands on a trigger hair (or when a human touches a pencil tip to a spike).
Bladderworts (Utricularia) produce a multitude of small bladders with trap doors that serve as the mouth of the plant. When an organism touches its grasslike leaves, this opens the trap door creating a partial vacuum that sucks the organism inside. The door shuts, leaving no chance for escape and the plant begins digesting the organism.
Drosera, also known as sundews, attract insects with brightly-colored glands found on the stalks of this plant. The glands ooze sticky nectar that glues the landed insect to the leaf. On many sundews, the entire leaf coils around the prey during the digestive process. The English Sundew (D. anglica) is a Zone 4 to 10 plant that might grow outdoors here if given the proper microenvironment.
Another carnivorous Zone 3 to 10 plant that could grow here outdoors is the butterwort, Pinguicula vulgaris. Its basal rosette of sticky, succulent leaves traps small insects and closes in around the prey while digesting it. This plant shoots up a tall stem containing a white-throated violet flower.
Nepenthes is a genus of complex pitcher plants. Its long vines snake through the undergrowth and trees and end in a tendril with an intriguing pitcher hanging down to entice insects inside. This plant captures and digests small invertebrates and vertebrates.
Other interesting carnivorous plants are cobra lilies (Darlingtonia Californica), rainbow plants (Byblis) and huntsman's cup/horn (Sarracenia).
If you attempt to grow carnivorous plants in your home or greenhouse, try to replicate their natural warm, humid environment. Terrariums seem to work best.
To see some of these exotic plants, check out the exhibit at the Denver Botanic Gardens on your next trip to the big city.
Deb Babcock is a volunteer Master Gardener through the CSU Extension Routt County. Call 970-879-0825 with questions.