923 Dionaea muscipulaCommon Names: Venus flytrap Family: Droseraceae (sundew Family)
The Venus flytrap is a small herbaceous wetland plant characterized by unique hinged clamshell-like traps that spring closed to catch unwary insects. Venus flytrap grows from a fleshy white rhizome which gives rise to 4-6 in (10-15 cm) rosettes of reclining leaves. Each leaf consists of a relatively broad petiole (leaf stem) and a leaf blade which is modified into the trap. The perennial Venus flytrap blooms in May and June with white, five-petaled blossoms which are held a few inches above the foliage. About 6-8 weeks after flowering, the ovoid fruiting capsules mature, each releasing many tiny black seeds.
The trap of the Venus flytrap is one of Nature's most amazing marvels. The outer edges of the two clamshell-like halves are lined with nectar glands and stout bristles. They are normally held open at about a 60 degree angle, exposing a green, pale yellow or maroon lining. When an insect is attracted to the sweet nectar and enters the interior of the trap, it brushes against sensitive trigger hairs causing the two halves to close rapidly, trapping the unwary creature in a barred jail behind interlocking bristles. If the stimulus was just a raindrop or piece of debris, the trap opens back up; but if it was an insect, the trap closes tighter and the interior secretes digestive enzymes. Depending on air temperature and the size of the meal, it is digested and absorbed in 3-5 days. Then, the trap reopens for another dinner guest.
Venus flytrap, Dionaea muscipula, is native to bogs and wet seepage areas that lie between longleaf pine savannas and shrub bogs (pocossins) on the Coastal Plain in the vicinity of Wilmington, North Carolina - from the Santee River in Charleston County, SC, to Beaufort County, NC. Periodic fires are required to maintain this habitat type and to prevent encroachment by shrubs and trees which would quickly shade out the flytraps. (These lightning-set fires are a naturally occurring element of the landscape, and many kinds of plants and animals are adapted to them and even require fire for their longterm survival.) Within their naturally small range, flytraps also grow on roadsides that are sandy and perpetually wet. (Road shoulder mowing replaces periodic fires here.) Venus flytrap has been introduced, and has become naturalized, in seepage bogs from the Florida Panhandle to Pennsylvania and the New Jersey Pine Barrens.
CultureVenus flytrap is relatively easy to keep alive in a terrarium for a few weeks, but few people have a green enough thumb to keep one alive for more than a year. But it IS possible, and the plants have been know to live for more than 20 years! Light: Outdoors, Venus flytrap thrives in full to partial sun with protection from full midday sun. Containerized plants need bright light. Moisture: Venus flytraps require a substrate that is constantly moist and an atmosphere with at least 80% relative humidity. They can tolerate brief periods of flooding and drying out. During the growing season, keep the planting medium constantly moist. During the winter, keep it just barely moist. Never water with anything but rain water. Hardiness: USDA Zones 6 - 8. The natural range of Venus flytrap includes only Zones 7B and 8A, but introduced populations have thrived from zones 6 to 8B. Venus flytraps usually die back to the ground in winter, but they will remain evergreen in protected sites and warmer climates. The typical heated home is too warm for Venus flytrap in the winter, when they should be kept no warmer than 40º F (4º C) In the summer, they do best when temperatures stay below 80º F (26 º C). Propagation: Fresh seeds germinate readily when sown on a suitable substrate. Seedlings take 3-4 years to mature to flowering stage. Venus flytrap is easy to propagate from leaf cuttings taken in spring or summer and inserted in damp sand. Plants also can be divided.
Venus flytrap can be kept alive in cultivation, but not in an open flower pot in the living room! These plants require cool temperatures, a constantly moist substrate and a humid atmosphere. Grow in a cool greenhouse or in a terrarium in bright light. Use an acidic potting medium of equal parts peat moss (sphagnum) and sand. Feed flies or other little insects every few days during the growing season. Keep temperatures below 80ºF (26ºC) in the summer and 40F (4ºC) in the winter.
Each trap can catch and digest a prey item just 2-4 times during its life time (only once if it's a really big bug). The traps have a limited number of false alarms too, so don't stimulate them too often. After about a 10 false closures they will no longer respond. New traps are produced all summer, though..
Wet seepage areas and sphagnum bogs, with their luxuriant growth of mosses, sedges, pitcher plants and sundews may appear to be rich in organic matter, but looks can be deceiving. The water is constantly leaching away nutrients and its highly acidic reaction hinders a plant's ability to take up nutrients from the soil. Thus the native habitat of Venus flytrap and other carnivorous plants is actually deficient in several elements that are essential to plant survival. These essential elements include potassium, calcium, and especially nitrogen, the building block of all proteins. Many plants that live in this environment have evolved the ability to trap small animals (often insects or tiny crustaceans) and digest them in order to obtain the nutrients they need. Pitcher plants (genera Sarracenia and Darlingtonia) trap small animals in watery pitfalls where they are digested by the plant's enzymes. Butterworts (Pinguicula) and sundews (Drosera) are covered with tiny sticky glands; unwary insects get stuck to the "flypaper" surface and are slowly digested. The aquatic bladderworts (Utricularia) have tiny rounded capsules with flaplike "trap doors." When stimulated by a nearby crustacean or insect, the door springs open, sucking water, along with the hapless prey, into the capsule. The Venus flytrap is the Western Hemisphere's only carnivorous plant with closing "beartrap" type doors. It is also the only species in its genus.
Because of habitat loss and overcollecting for the plant trade, Venus flytrap is becoming an endangered species, and collection from the wild for commercial purposes is unlawful throughout its native range.
Steve Christman 4/12/01; updated 3/18/03, 10/26/03