Carnivorous plants stoke the imagination and spawn Hollywood films. They have bizarre adaptations to aid in the absorption of nitrogen in the nutrient poor environments in which they live. Venus Fly Traps are perhaps the most famous, their moving lobes snapping shut like a purse around the insect prey to be digested. The far more numerous Pitcher plants produce a simple pit trap. Butterworts and sundews both deploy sticky hairs to ensnare prey. There are other carnivorous plant types, but here in Utah we have only 3 species of Bladderworts in the genus Utricularia.
Our three species are denizens of the water, and as such are scattered among the ponds, lakes and sluggish creeks of the state. Their finely divided leaves efficiently capture sunlight. Bladderworts are often found floating freely on the water surface. Despite their aquatic nature, bladderwort flowers are showy and held above the water surface to attract pollinators with their yellow loveliness.
How can an aquatic plant be carnivorous? The plants produce bladder-like utricles along the underwater stem that look much like cancerous growths. These hollow bladders have tiny hair-like extensions that respond to motion. When stimulated by any wee swimming creature, the hairs cause the flattened bladder to inflate, sucking in both water and prey.
Of all the carnivorous plants, Bladderworts are the easiest to grow … a warm aquarium and some pond mud is all that is needed to keep a Bladderwort happy and healthy. So next time you visit one of our natural ponds or lakes, look for these carnivorous plants. You may even hear the faint crackling sound of the utricles closing as you lift them from the water.
This is Linda Kervin for Bridgerland Audubon Society.
Photos: Courtesy US Forest Service, Photographer Barry Rice http://www.sarracenia.com/
Text: Michael Piep, Utah State University: Intermountain Herbarium http://www.herbarium.usu.edu/
Southwest Colorado Wildflowers, Photos of Utricularia: Enlarged Photo Pages/utricularia.htm http://www.swcoloradowildflowers.com/Yellow%20Enlarged%20Photo%20Pages/utricularia.htm
Utricularia – The Bladderwort, Carnivorous Plants Online – Botanical Society of America http://www.botany.org/carnivorous_plants/utricularia.php