It is fascinating that certain members of the Plant Kingdom evolved to capture and ingest members of the Animal Kingdom.
To adapt to the nutrient-deficient, acid soils of swamp life, carnivorous plants attract, capture, kill and digest insects to obtain nutrients from their prey.
They still carry on photosynthesis like other plants and carnivorous plants can live for quite a while without the nitrogen and minerals absorbed from insects. However, like other plants, they are healthier with proper nutrition.
Carnivorous plants are in a continuous stage of growth with old leaves turning black, dying and falling off as new growth appears. In the colder months of the year, they go dormant. With the return of spring and long, sunny, humid days, these plants thrive and flower.
All attract insects through odor and color, but their mechanisms for ensnaring food varies, somewhat. Pitcher plants do not move, but lure insects into its pitfall trap with the sweet scent of nectar. Sundew and Butterwort capture insects rather like flypaper and then, their leaves envelop their stuck victim. Venus’ flytrap employs the steel trap method by snapping shut after an insect touches its ‘trigger hairs’.
All can be found in the Green Swamp Ecological Preserve, which awaits exploration. Please be advised, in most cases, it is illegal to collect carnivorous plants growing in the wild.
Pitcher plants (Sarracenia species) are the largest carnivorous plants and easiest to spot. Found mostly along the Coastal Plain from North Carolina to Louisiana, but they are infrequent.
The leaves of pitcher plants form a hollow tube or pitcher, which normally contains water, enzymes and digestive acids. The top of the pitcher is often completely or partially covered by a ‘hood’, which helps to attract prey and control the amount of rain water entering the tubular portion.
Insects fall into the liquid and are absorbed after digestion. Tiny, downward hairs line the inside of the pitcher making escape nearly impossible. (Wasps, in particular, are said to be attracted to pitcher plants.)
The Drosera genus has seven North American species of sundews varying in size. The small sundews of southern swamps require a keen eye. Generally, they grow close to the ground with the leaves in a pinwheel shape, which look like a flat, red blotch underfoot.
Upon close examination, the leaves have several tiny feelers or tentacle-like projections. At the end of each projection is a gland that secretes a clear drop of liquid. This sticky fluid gives the plant it’s sparkling, dewy appearance and traps its quarry.
The tentacles envelop the insect for digestion. Interestingly, the plants are said to have the ability to differentiate stimuli because they only close around insects and not sand, water, or other objects.
Yellow butterwort (Pinguicula lutea) is another species of carnivorous plant that resides in pine savannas of the Coastal Plain. A single, upright stem with a yellow flower peeking out of the wiregrass is the only thing that alerts passers by to the plant’s presence in the spring.
Move the wiregrass a bit to see the cluster of fleshy leaves at the base of the plant, which it uses to trap insects. The oblong-shaped leaves are each pointed at the tip and have curled edges.
Insects become stuck in the mucilage of the hairy, glandular leaves. Over time, the plant enfolds its prey, releasing enzymes to digest the softer parts of the insect.
Venus’ flytrap (Dionaea muscipula) is the most well-known of the carnivorous plants. It is only native to this area [i.e. southeastern North Carolina within about seventy-five miles of Wilmington] and is federally protected.
A small cluster of white flowers on about a ten inch stalk sprouts in the springtime. Any other time of the year, spotting the plant in the wild requires looking closely at the ground for the rosette of clam-shaped leaves.
When the trigger hairs around the edges of the leaves are stimulated, the two-sided leaf closes around its quarry. To close, two trigger hairs must be touched or the same one touched twice.
Then, the plant secretes digestive fluids and absorbs the nutrients it needs from its prey, which takes between three to five days. The leaf (or trap) dies after closing and opening three times. If the trap was stimulated and closed empty (or with something other than a meal in its clutches), the leaf re-opens after a days time.
Previously published by The Brunswick Beacon in Island Living. Reprinted with permission.