When Barry Rice feeds the strange-looking plants in the Botanical Conservatory greenhouse on campus, he doesn't dip into a bag of fertilizer. The bugs buzzing around will do, thank you.
Rice, a scientist with the Nature Conservancy's office at UC Davis, is fascinated with carnivorous plants -- that is, meat-eating plants. The conservatory includes a "Little Shop of Horrors" -- straight out of that 1986 cult film classic -- where more than 100 species and over a 1,000 meat-eating plants are thriving under Rice's watchful eyes and nurturing hands.
"There is a lot of weird stuff in the plant world," grins Rice, an Illinois native who has worked on campus since 1997. He quickly credits a cadre of conservatory volunteers for stewarding the leafy meat-eaters. They are no ordinary plants, to be sure.
As Rice explains, a plant is carnivorous if it attracts, captures and kills animal life forms. It must also digest and absorb the nutrients from the prey to qualify.
Rice didn't always envision a career in botany. He was a physics undergraduate student and an astrophysics graduate student. Then one summer he poked a Venus flytrap with a pencil, watched its "jaws" close, and fell in love with the predatory plants.
"The Venus flytrap was my gateway drug to the plant world," he jokes.
Rice, who has grown thousands of carnivorous plants, relished the immediate impact he could have on plants, a contrast with distant stars and galaxies.
Rice's green-thumb work on carnivores will be available Oct. 2 at the annual Plant Faire held by the UC Davis Arboretum. The sale will include carnivorous plants from the Botanical Conservatory. "The carnivorous plants are so popular," says Rice, "that almost a third of what we take over there is sold five minutes after the sale begins."
The Nature Conservancy provides funds to the university to allow for Rice's presence on the Davis campus as a member of the Wildland Invasive Species Team. In his spare time he edits the Carnivorous Plant Newsletter, which is the journal of the International Carnivorous Plant Society.
Carnivorous plants date back to the age of the dinosaurs more than 100 million years ago. More than 600 species and subspecies of the plants exist throughout the world. Native Californian carnivorous plants include the Californian cobra lily, round-leafed sundew, English sundew, obovate-leaved sundew, Del Norte butterwort, and a number of bladderworts, some of which are native to the Central Valley.
Science doesn't fully understand the dynamics of meat-eating plants, Rice says. One reason is that these curiosities have been considered just that, novelty plants, and not taken as seriously by many botanists. For example, Rice points out, "we don't truly know why they need the nutrients associated with insect meat."
Rice and fellow researchers, staff and associates at the conservatory are exploring a variety of carnivorous plant issues, from how to grow hybrids to quickening the rate of propagation for the mostly slow-growing plants. It's not as simple as giving them hamburger (which, by the way, would only damage the plants).
The plants have to work for their food. Mostly growing in nutrient-poor soils, carnivorous plants must secure their minerals by using their leaves to trap insects.
Rice notes that Venus flytraps don't automatically close on just one poke -- which could be but a raindrop -- but need to feel a couple "wiggles," the motion an insect trying to escape would make, in order to snap their traps.
"This is a plant that can count," says Rice. "Oak trees can't count."
Rice is especially fond of the pitcher plants, or Sarracenia. Their colorful leaves attract flies, bees and moths. Nectar along the opening of the pitcher lures the insects inside, where they are trapped and digested.
There are also the sundews, Drosera, which are plants with hundreds of tentacles that secrete a sticky, glue-like substance through their tentacles -- trapping the insect while leaves close up over it.
What is the biggest meat-eating plant? One species of the pitcher plant (Nepenthes bicalcarata) can grow large vines more than 10 yards long, Rice says. It's been known to capture creatures as large as frogs or sometimes sick rodents. Nepenthes are mostly native to Southeast Asia.
And the most bizarre? Rice points to a small, harmless-looking plant, the Genlisea or "corkscrew" plant. From tropical Africa, Madagascar and South America, they grow as terrestrials or semi-aquatics. Oddly, the meat traps are underground in small, bristly-shaped corkscrew structures that come equipped with digestive chambers. "They eat things as small as protozoans," Rice says.
Hard times for meat-eaters
Despite the hardiness of carnivorous plants, all things are not well in the leafy-meat-eater world, Rice says. Habitat loss is shrinking the numbers of these natural marvels. The Venus flytrap, for example is almost extinct in the wild.
"We've drained so many wetlands," Rice says. "We lost about 95 percent of the native wetlands in the United States, and this is the habitat most associated with carnivorous plants."
Carnivorous plants do not fare well in soil high in nutrients, a condition caused by agricultural runoff, pollution and human activity, Rice says.
He notes that the extremely rare pitcher plant, Nepenthes clipeata, will probably go extinct within the next 20 years.
Surprisingly, it's not the dark heart of the Amazon River Basin but the Southeastern United States that has been among the most fertile places on the planet for carnivorous plants. The bogs and swamps in that region, however, are quickly disappearing, Rice says.
"People love to drain swamps for some reason," he says. "They call it a 'reclamation project.' We're not reclaiming anything, but literally losing ground for our vanishing wildlife, both plant and animal."
On top of this, poaching is a major problem, Rice adds. Many people trek into the wilds, illegally dig up carnivorous plants, and sell them for profit.
For Rice, conservation is a family affair. His brother, Kevin Rice, is a UC Davis professor of agronomy and range science and an authority on the ecology and genetics of grassland and woodland plant species. And Rice and his wife, Beth, love nature so much they spent five days during their honeymoon canoeing around the Okefenoke Swamp in southern Georgia.