The Venus flytrap (Dionaea muscipula) is one of the few plants capable of moving fast enough to trap live animals. It has modified leaves that look like a clamshell and are able to detect movement and close when prey walks across them. The traps are sophisticated enough to differentiate between live prey and accidental touches from falling leaves or raindrops. Venus flytraps are rare in the wild and found only in a tiny area of the United States, although they are widely sold as a curiosity in gardening centers. Cultivated plants can live for over 20 years but need fairly specialized care.
Adult plants grow to a maximum of 6 inches across and never have more than 12 individual leaves growing out in a rosette from a fleshy, underground stem. Each leaf has a broad, green section for photosynthesis tipped with a clamshell-like lobe fringed with long bristles. The upper parts of the two halves of this trap are deep red in color with small trigger hairs on their upper surfaces. The small, white flowers are borne on the end of a stalk about 4 inches high, followed by small black seeds about the size of a period.
Venus flytraps are limited to a tiny area of North and South Carolina within 60 miles of the town of Wilmington, although there are naturalized populations in northern Florida and New Jersey.
Within its tiny range the Venus flytrap grows in pine savannas and shrub bogs with wet or waterlogged, acidic soils. Periodic natural fires keep these ecosystems free of tall vegetation and allow the Venus flytrap, which requires a lot of sunshine, to thrive. The species is also found along wet roadsides that are regularly mowed.
The key to growing Venus flytraps is to duplicate their natural environment as closely as possible. They need a combination of bright light, high humidity and wet, acidic soil to thrive. Potted examples are best grown on a bright windowsill with some direct sunshine. The pot should be placed on pebbles in a saucer of water to maintain humidity and the plant misted regularly. Venus flytraps need to be watered and misted with rainwater or distilled water and should not be allowed to dry out.
Most plants bought in shops and gardening centers are stressed and damaged and many only survive for a few weeks even if provided with ideal conditions. The plants also go through a fall dormancy period when they stop producing new leaves.
Adult Venus flytrap plants will occasionally divide spontaneously into separate rosettes. It takes at least two years for them to separate completely and develop their own root systems and they should not be separated before then. Venus flytrap seeds will germinate if sown on the surface of moist peat moss. Fresh seeds need a period of cold before they will germinate and should be kept in the refrigerator for a few weeks prior to sowing. Adult plants will occasionally produce a flower stalk tipped with several small plants instead of flowers. These plantlets should be left on the plant as long as possible and planted in damp peat at a depth that leaves the leaves resting on the surface of the substrate.