|
|
|
A plant that is carnivorous attracts, kills, and
digests animal life forms. Some plants may have some of these
characteristics, but in order to be considered truly carnivorous,
a plant must exhibit all of the above traits. Native to mineral-poor
soils, these plants have developed modified leaves which have
the ability to absorb nutrients from insects they digest. The
modified leaves form traps to lure, capture and digest prey.
There are four types of traps in seed-bearing carnivorous plants:
the closing trap, the pitfall trap, the trapdoor, and the flypaper
trap. |
|
The Venus Fly Trap, photo upper left, is
an example of the closing trap. The trap leaves consist of two
halves resembling a clamshell. Each exhibit a bright reddish
color which helps to lure in the prey. Nectar glands along the
leaf margins also attract prey. Each inner half has three smaller,
finer trigger hairs in a triangular pattern which, when properly
stimulated by an exploring insect, initiate trap closure. Once
the insect has been captured, the digestive glands secrete juices
and absorb nutrients over a span of 3 to 5 days. The trap will
reopen after digestion is complete.
Pitfalls, as displayed by Pitcher Plants,
are a second type of trapping mechanism found in carnivorous
plants. The modified leaves of these plants are tubular, and
when the prey is lured to the opening, it enters or falls in
and is unable to escape. The inside of the pitcher has a slick,
waxy lining and there are numerous hairs pointing downward to
prevent escape of the prey. The digestive glands are located
at the bottom portion of the pitcher.
Sundews and Butterworts have the flypaper,
or adhesive trap, with numerous sticky glands covering the upper
portion of the leaf. Small insects become intangled in the sticky
"dew" and the leaf then curls up to trap and digest
the prey. |

Sarracenia purpurea- Pitcher Plant

Nepenthes - Tropical Pitcher Plant
Photos by: Andrew G. Seymour |

Utricularia longifolia - Bladderwort
Flowers
Photo by: Andrew G. Seymour
|
The trapdoor is an aquatic trap that has
a flaplike door over a small entrance at one end. Bladderworts
are an example of carnivorous plants that utilize these types
of traps. The traps, or bladders as they are called, are bulb
shaped with the opening surrounded by numerous hairs. Prey brushing
by the sensitive hairs will send a signal for the bladder to
expand, sucking in the prey and for the trapdoor to close.
Flowers of most carnivorous plants take
second place in attention to the trap leaves. However, in case
of the bladderworts, the flowers may be the most noticable part
of the plant, and the part most easily used for identification.
The leaves of bladderworts are minute and branching, with the
majority of the plant below soil. |
|
|