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Nematology (Botany) Circular No. 40 Fla. Dept. Agric. & Consumr services
June 1978 Division of n f ry
VENUS' FLYTRAP, DIONAEA MUSCIPULA, Unive s&y of Flrida
A PLANT WHICH EATS INSECTS
K. R. Langdon
It has been said that when a dog bites a man, that isn't news, but when a man
bites a dog, that is news. The Venus' flytrap, Dionaea muscipula Ellis, is in
the "man bites dog" category. Most plants are eaten by some type of insect.
Venus' flytrap actively catches and consumes insects.
Dionaea muscipula (fig. 1) is a small perennial
plant growing naturally only in a small area of
the wet, sandy, coastal plain savannahs of the
Carolinas within an approximate radius of 60-75
miles from Wilmington, N. C. The plant grows
from a white, somewhat elongated, bulbous rhi-
zome. A rosette of leaves is produced which may
measure up to 10-14 cm across with leaves up to
12 cm long. The leaves consist of 2 parts; a
broad, leaf-like petiole which performs most of
the photosynthesis, and a blade which is modi-
fied into a trap to catch and digest insects.
The white actinomorphic flowers, borne on a 1-30 "
cm scape, are about 1.0-1.5 cm across. After
fertilization of the flowers, seed pods are form- Fig. 1. Dionaea muscipula
ed containing tiny, black, pear-shaped seeds,
which mature in 6-8 weeks.
Seed will germinate immediately on ripening if planted on a suitable medium.
Seed stored at room temperature loose viability in about 2 months, but can be
kept viable for up to a few years if properly dried and refrigerated.
The most interesting part of the plant is the trap. It consists of 2 halves
which have the appearance of being hinged. The halves move by bending, rather
than moving on the hinge as might be expected. Each half of the trap has a
line of stiff hairs along the margin which on closing form an interlocking
closure. On the face of each half are usually 3 trigger hairs. Movement of
these hairs by prey insects causes the trap to close.
Once the trap closes on an insect, the halves continue closing tighter until
tight contact is made with the insect and the margins are tightly closed. Tiny
gland cells on the inner surface of the trap begin secreting digestive juices
to digest the insect. As the insect is digested, the nutrients are absorbed by
these same glands over a period of 3-5 days. Afterward the trap reopens. If
the trap is triggered, but no prey is caught, the trap will reopen within a
few hours. Trapped insects are necessary as a nitrogen source when the plants
Contribution No. 182, Bureauof Nematology, P. O. Box 1269, Gainesville, FL 32602
are growing in the poor soils of their natural habitat. Under cultivation, if
adequate nitrogen and other nutrients are provided and if other cultural re-
quirements are adequately met,~trapped insects are much less important, if nec-
essary at all.
The Venus' fltrap ist.1tquent y sold as a household pot plant. This is unfor-
tunate because the plIn*se-ravely survive pot conditions for any prolonged period
of time. They are very exacting in their cultural requirements and must have
acid bog conditions closely approximating those of the area where they grow
naturally. Any appreciable deviation from this will mean a short life for the
The range of Venus' flytrap, which has never been very extensive, is decreasing
rapidly because of destruction of its habitat for development etc., and from
over-collection for sale.
The Venus' flytrap is an interesting plant to grow and observe, but it definitely
is not suitable for any grower not thoroughly familiar with this plant and its
Heslop-Harrison, Y. 1978. Carnivorous plants. Scientific American 238(2):104-
Lloyd, F. E. 1976. The carnivorous plants. Dover, New York. 352p.
Schnell, D. E. 1976. Carnivorous plants of the United States and Canada. Blair,
Winston-Salem, N. C. 125p.