by Whit Gibbons

March 16, 2014

Joab Thomas, who died on March 3 at the age of 81, was an excellent botanist whose advice was worth listening to. He once told me that my newspaper columns on ecology had too few plant examples compared to animals. That's because, on the whole, animals tend to be action figures whereas plants are mostly inert unless the wind is blowing. But intriguing plants do exist, and I dedicate this column to Joab.

Plants kill and eat millions of animals every year. In addition to having a wide diversity of insects on the menu, carnivorous plants eat other animals, including small birds, frogs, and mammals. Plants that capture and digest animals occur in many parts of the world, and several kinds can be found in North America.

Pitcher plants, in which insects fall into a highly effective pitfall trap, are among the best known. In some, the column, or "pitcher," is only a few inches high, but it can be almost 3 feet tall in the yellow trumpet pitcher plants.

With downward-pointing hairs around the lip of the column and digestive liquor at the bottom of the flask, pitcher plants mean certain death for many insects. The bug that makes a misstep over the edge of the tube will soon become part of the plant world, as it is digested and absorbed.

The most spectacular pitcher plants are from Mount Kinabalu National Park in Borneo, a region with the greatest concentration of pitcher plant species in the world. One of these, the rajah pitcher plant, has tubular flasks large enough to capture rats, and it can hold more than a quart of digestive fluid.

Some plants produce their own heat internally, a trait usually reserved for birds, mammals, and a few other animals. Perhaps the best known U.S. plant with heat producing properties is the eastern skunk cabbage.

In the Northeast, skunk cabbages are among the earliest plants emerging in the spring, often pushing directly up through a covering of snow that is melted by their generated heat.

Some skunk cabbages have been reported to raise their temperature 45 degrees higher than their environment.

Another heat-producing plant is the voodoo lily, a tropical species of Southeast Asia. With a beauty typical of other lilies, the voodoo lily has a striking purple flower and reaches a height of almost 3 feet.

Despite their ornamental appearance, voodoo lilies have a trait that might diminish their popularity in the garden. During the period of pollination, the flowers heat up. Temperatures inside a flower in the cool shade can reach 110 degrees F, at which time, the plant smells like rotting meat.

One animal trait we are often interested in is size. How long is a python? How tall is a polar bear standing on its back legs? How much does a largemouth bass weigh? What about plants - what is the biggest flower in the world?

The answer: Rafflesia. Found in Indonesian rain forests this plant truly qualifies as bizarre, because all you see is flower. It has no leaves, no limbs, no roots.

In fact, Rafflesia does not even have chlorophyll. It is just a giant, eye-catching flower that can be more than 3 feet in diameter and weigh more than 40 pounds. It has parasitic filaments that feed off the roots of a particular species of vine.

I first learned about all of these plants when I took a course in plant taxonomy from Joab Thomas. All serve as superb examples of the diversity of life among plants and the many secrets and mysteries that await our understanding.

He was an amazing individual. Having been president of the University of Alabama and later at Penn State, he became best known to many as the only person to have been the boss of both Bear Bryant and Joe Paterno.

In contrast, he was known to me and many colleagues as an outstanding botany teacher who could actually make people realize that plants are exciting.

If you have an environmental question or comment, email

(Back to Ecoviews)


SREL HomeUGA Home SREL Home UGA Home