Dionaea muscipula (Venus fly trap, "Haetorigusa")

Japanese name: ハエトリグサ （蠅捕草）
Scientific name: Dionaea muscipula

[Overview]
A carnivorous perennial 5–10 cm tall, growing in shallow wetlands.
The leaves are basal and form a rosette. Each is a kidney-shaped round trap resembling a bivalve shell, with thick, long bristles lined up along the margin.
The inner surface of the leaf is often tinged red.
The leaf stalk is flat and broad.
On the inside of the leaf there are 3 sensory hairs on each side. When two or more of them are touched at the same time, or one is touched twice, the leaf snaps shut and catches its prey.
At this time the bristles on the leaf margin interlock so that the prey cannot escape.
The complicated closing mechanism is thought to be an adaptation that prevents false triggering when something other than prey touches the leaf and ensures that prey is reliably caught.
A leaf that has caught prey is completely closed by the next day. The bristles curve back, the prey is crushed inside the leaf, and digestive enzymes are secreted to absorb the nutrients.
A single leaf can open and close only about 4–5 times, and if it is touched needlessly and made to close, the plant becomes exhausted and dies.
A flower stalk 15–30 cm long stands upright and bears 3–10 white five-petaled flowers about 1–1.5 cm across in an umbel or cyme.
The fruit is a spherical capsule, and the seeds are glossy black.

[Cultivation]
Propagate from seed or by division; sow seed as soon as it is harvested.
It prefers a constantly moist, nutrient-poor, acidic environment, so it is best planted in sphagnum moss.
It dislikes high temperatures and dry wind.
In summer keep it cool in partial shade; in other seasons give it plenty of sun; in winter expose it to low temperatures in a place that does not freeze so that it goes dormant.
Water by standing the pot in a shallow tray of water, keeping the planting medium constantly moist.
Fertilizer is not particularly necessary.
There are no particular pests or diseases.

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