Monday, October 1, 2007

Carnivorous Plants










The Conservatory of Flowers in San Francisco is currently running it's carnivorous plant show called "Chomp." The event started in May, and will end November 4th. The plants are on loan from California Carnivores in Sebastopol.

The main plants on display are flytraps, pitchers, sundews and bladderworts. Over 600 types of carnivorous plants have been discovered in existence, although many are now extinct.

Carnivorous plants live on almost every continent (except Antarctica) and in every state in the U.S. Most are rare, and poaching (stealing plants from the wild) is common. Housing developments, the loss of peat bogs (sold as peat moss in stores), acid rain and global warming contribute to the loss of plants. Sadly, only 3-5% remain in the wild.

Q. Why do carnivorous plants capture flies and other insects (and sometime lizards, frogs and small monkeys)?

A.
The places that carnivorous plants live are usually low in soil and water nutrients. Over time these plants developed features (leaves) that capture insects to add in their diet.

Types of plants and their trapping methods:
1. The Venus Flytrap: when small trigger hairs on the leaves are touched twice within about 30 seconds, a trap will close within one second. Then, the trap tightens and finally seals.

2. The Pitcher Plant: has small pitchers (actually leaves) that are inviting to insects. Once an insect crawls into the pitcher, it is difficult to crawl back out. Tiny hairs all point downward to the bottom of the plant, which is often filled with digestive juices.

3. The Sundews: these plants have a sticky substance on tentacles attached to their leaves. The "dew" is a mixture of nectar, adhesive compounds and digestive juices. Insects literally stick to them like flypaper.

4. Bladderworts: a curious plant whose interesting behaviour was discovered in 1876 by a woman scientist named Mary Treat. The trap is set by the action of pumping water out of the bladder, resulting in lower water pressure inside. An insect that bumps against the "door" of the bladder triggers the bladder and sucks the insect in within 1/30th of a second! The "door" then shuts behind them, sealing them in forever, BWAH HA HA! (couldn't help that) Scientists are still not exactly sure if the insect is attracted to the plant or just wanders by.

The site below mentions places where you can visit these plants that are complete with boardwalks for viewing. Venus flytraps are indigenous to North and South Carolina. They have been introduced to other states though, and can be found growing in other states.

Growing carnivorous plants isn't easy. I have never tried, but after viewing the exhibit am enthusiastic about purchasing some. It's important to buy plants from reputable nurseries who do not collect specimens from the wild. This link will list several places worldwide that carry specimens checked by a reputable source. http://www.sarracenia.com/faq/faq6280.html

Here is the start of that website for easier navigation: http://www.sarracenia.com/faq.html

above photos by Holly Guenther