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The dodder plant is on the US Department of Agriculture's list of the ten most noxious plants.
The dodder, which also known as the strangle weed, is a parasitic plant. It has no root system and when it germinates it immediately needs to track down a host plant to live on. It only has a few days to do this. The dodders' favorite cuisine are vegetables such as tomatoes, onions and carrots and even citrus trees.
Once it finds a suitable plant, the shoots of the dodder coil around its victim allowing it to sink a needle-like apparatus into the plant and feeding off the prey, often killing it. (Who needs science fiction with this type of plant, right here on earth.)
Farmers have a difficult time getting rid of dodder because the same herbicide needed to kill this weed will usually harm the host plant.
Scientists originally thought the dodder just randomly sent out shoots looking for a victim.
But in an effort to find better ways to eradicate the pesty weed, a group of scientists from Pennsylvania State University experimented with the Cuscuta pentagona dodder. Their results were published in the September issue of Science journal.
They discovered that the dodder can actually smell. Well, not smell in the traditional sense of the word, but somehow it is able to pick up the chemical residue of potential prey and grows towards it.
The shoots of the dodder move around in a circular motion until it picks up the smell of a victim and creeps toward it.
When a Dodder plant was placed near tomato plants, for example, the scientists discovered that 80% of the time the dodder headed right for them. When they put fake tomato plants in the soil near the dodder, it was ignored.
It's also a fussy eater.
When researchers gave the dodder a choice of between wheat or tomatoes, it chose tomatoes. It avoided wheat because it produces a chemical the dodder dislikes. But if it doesn't have a choice, the dodder will suck it up and head for the wheat plant.
Source: Associated Press / Image: Japanese dodder infesting a tree Source: Kim Camilli, Texas Forest Service, www.forestimages.org
One of the big problems facing evolution is the intricate design where you have a number functions needing to work in tandem in order for the species to survive. This requires multiple evolutionary developments, simultaneously. Of course, when they can't explain how happened, they simply add another 100 million years to the evolutionary cycle, to allow for more random chance.
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