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The Premier
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Gardening with Carnivorous Plants
There is an unbreakable link between insects and plants. Neither
could exist without the other. Bees, wasps, and butterflies benefit
plants by pollinating their flowers. Other insect species feed on
plants by sucking sap from plant tissue or by devouring plant parts.
However, in a fascinating twist of nature, there are a small number of
plants that "eat" insects. The diet of these plants also includes
mites, sowbugs, and occasionally small animals, such as frogs. In every sense, these flesh-eating plants are true carnivores.
Carnivorous plants don't survive solely by "eating" insects and other
prey. Carnivorous plants contain chlorophyll and
manufacture food via photosynthesis in the same way as all green plants . Insects and other small creatures
are simply a supplemental food source for carnivorous plants.
The Venus' fly trap, pitcher plant, and sundew are carnivorous plants
that make fascinating houseplants.
Venus' Fly Trap
The Venus' fly trap (Dionaea muscipula) is native to a small coastal
area in North and South Carolina. The plant consists of a rosette of
flattened leaves. The upper portion of each leaf has a trap-like
structure. The two-lobbed trap is hinged down the center and fringed
with long, teeth-like projections. The inner surface of the trap is
dark pink to red. There are also 3 trigger hairs on the inner surface
of each lobe.
Nothing happens if only one trigger hair is touched by an
insect. However, when one trigger hair is touched twice or when two are
touched in succession, the trap closes. The teeth-like projections
interlock, trapping the unsuspecting victim inside. The struggling
victim stimulates the secretion of digestive juices. These juices
digest the soft parts of the insect. Only the hard, indigestible parts
of the insect remain when the trap reopens in about 10 days. The open
trap then awaits its next victim.
Pitcher Plant
There are several genera (groups of plants with common traits) which
are referred to as pitcher plants. The genera Sarracenia and
Darlingtonia are native to North America. Plants in the South American
genus Heliamphora, the tropical Asian genus Nepenthes, and the
Australian genus Cephalotus are also called pitcher plants.
All pitcher plants have modified leaves or leave parts that resemble a
pitcher. The pitcher- like structure holds water and is topped with a
hood or lid. Unsuspecting insects and other prey wander into the
pitcher. Escape from the pitcher is prevented by a smooth surface,
downward- pointing hairs, or inrolled rim. Eventually the trapped
victim falls into the water and drowns. The drowned victim is then
converted to plant nutrients by digestive enzymes in the water.
Sundew
There are more than 100 species of sundews (Drosera). Sundews are
mostly short- stemmed plants consisting of a rosette of foliage.
Depending on the species, the leaves vary from thread-like to
paddle-shaped to nearly round. The leaves are covered with tiny
(usually red) hairs. These hairs exude a clear, sticky fluid. (The
dew-like secretions give the plants their common name.) The sticky
droplets trap unwary insects or other small creatures that come in
contact with it. The struggling victim stimulates the hairs to bend
inward, drawing it closer to the leaf where it is digested into plant
nutrients.
Care of Carnivorous Plants
Carnivorous plants have more exacting requirements than most commonly
grown houseplants. Carnivorous plants require a moist, acidic growing
medium, high relative humidity, and bright light.
Excellent containers for carnivorous plants include a fish aquarium or
large terrarium. A piece of plexiglass placed over the top will help
maintain a high relative humidity. Ventilation can be provided by
keeping the plexiglass slightly ajar.
A suitable growing medium for carnivorous plants consists of 2 parts
sphagnum peat moss and one part coarse sand. If using a fish aquarium
or terrarium, place 1 inch of coarse gravel on the bottom before adding
the growing medium.
Good lighting is essential for carnivorous plants. An east or west
facing window that receives at least 1 or 2 hours of direct sun is
fine. A fluorescent light fixture containing two 40 watt tubes can be
used in poorly lit areas.
Day-time temperatures should be 70 to 75°F during the summer
and 55 to 60°F in winter.
When watering carnivorous plants, use rain or distilled water. Tap
water may be too alkaline or contain too many minerals.
Finally, there is usually no need to fertilize carnivorous plants.
These plants are native to areas with low nutrient levels. If you do
fertilize, a 1/4 strength solution of fish emulsion every 2 to 4 weeks
during the growing season should be sufficient. Do not feed them
hamburger.
Carnivorous plants are a fascinating group of plants. Their amazing
growth characteristics and ability to eat insects and other small
creatures are simply adaptations to their unique environment.
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