The mustachioed critter in the Dr. Seuss tale "The Lorax" might feel like a lone voice in the fictitious wilderness of felled truffula trees. ("I speak for the trees, for the trees have no tongues.") But the fuzzy orange guy has good company among real-life botanists and teams of conservation-minded volunteers across Texas who seek out imperiled plants almost as rare as the bright, fluffy truffula trees in the 1971 children's story that is now a movie.

"The people who work in conservation really are the Loraxes of the world. They are speaking for these plants," says Flo Oxley, former director of conservation at the Lady Bird Johnson Wildflower Center in Austin.

All have the same goal: They don't want to see plant species disappear. So they track down specimens so the flora may be preserved for posterity.

Gardens in Austin, San Antonio and Houston collect and propagate about 50 threatened species watched over by the Center for Plant Conservation, a St. Louis-based organization with 37 participating institutions in the U.S.

In Austin, the Wildflower Center maintains a bank of seeds for approximately 10 percent of Texas plants, about 600 species. That collection is a backup for the Millennium Seed Bank, a storehouse of 24,000 plants at England's Royal Botanic Gardens, Kew. Not all of those plants are currently threatened; the project is a safeguard to ensure the future of the world's basic habitat plants.

In San Angelo, botanist and water lily authority Ken Landon has preserved tubers of about 85 species of plants in the genus Nymphaea in the International Waterlily Preservation Repository.

At least 13 Nymphaea species have vanished in the past 20 years, says Landon, who has braved snakes, crocodiles and, just last month, gunfire while looking for plants around the world. After locating a rare specimen - often on private property - seed collectors need good timing.

"We collect them at the time they are being dispersed," Oxley says. "Any time before that, the seed won't survive. Any time after that, they are gone."

To be viable, seeds must be separated from chaff and dried to about 15 percent humidity so moisture inside them doesn't expand when they are frozen.

Inside foil envelopes, the frozen seeds at the Wildflower Center might well outlast the 18-cubic-foot Kenmore chest freezer where they're stored. It's not unrealistic, Oxley says, for seeds - particularly those from temperate regions - to remain viable for 1,000 years.

While a single plant might not seem important in a state with 6,000 species, losing one could have far-reaching implications.

"We have these complex ecosystems, and we don't know how all these species fit in," says Debbie Benesh, a botanist who's the plant research technician overseeing collections for the CPC at the San Antonio Botanical Garden. "If we knocked out one of these plant species, there might be a butterfly that uses only that species as its food source, and then we've wiped out that butterfly."

Minnette Marr, a plant conservationist at the Wildflower Center, cites Texas wild rice (Zizania texana), an aquatic grass resembling something that might have flowed from Dr. Seuss' pen. The plant, a habitat for the endangered fountain darter fish, grows only in about a 2-mile stretch of the San Marcos River that runs through Sewell Park. Most of its slender foliage is submerged in the crystal-clear water, so it looks like green hair flowing in the current.

"We wouldn't have a flow in that river if it weren't for the laws enacted to protect the Texas wild rice," Marr says. Because the plant is an endangered species, she explains, pumping from the Edwards Aquifer is limited to protect the springs that feed the river.

Some endangered plants benefit humans more directly, says Anita Tiller, botanist and conservation officer for the CPC at Mercer Arboretum and Botanic Gardens in Houston. Extracts from Correll's false dragon head (Physostegia correllii), one of 24 plants the arboretum tends for the CPC, have been shown to slow the growth of tumor cells. However, the wetland wildflower now only can be found at a site in Travis County and two or three places in Louisiana.

The Mercer Arboretum and the San Antonio Botanical Garden maintain displays of endangered plants so the public can recognize a tree or flower, like the Texas poppy-mallow (Callirhoe scabriuscula), that needs help.

The tall winecup grows only in Runnels, Coke and Mitchell counties on sand deposited tens of thousands of years ago when the Colorado River flowed at least as wide as the Mississippi River today. A property owner outside Ballinger let Marr and her colleagues dig the plants - and their 3-foot-long roots - when construction threatened their future.

The Wildflower Center harvested about 4,000 seeds from 54 rescued plants in 2010 and collected about 1,000 seeds in 2011, which was a drier year.

"That's the best of all situations," Marr says about the landowner who recognized the endangered plant. "There's no protection for an endangered plant on private property. If you had an endangered animal, there are laws that protect that and limit what you can do with your property. That's simply not the case with plants."

Even with that success, Marr's optimism about the Texas poppy-mallow's future is guarded. Because it grows on rare soil, it likely was never common. And now its habitat is disappearing as the sand is used for building materials. "It's really a double whammy. Not only are they taking the sand, but the seeds in that sand are going who knows where."

Marr is more hopeful about the bracted twistflower (Streptanthus bracteatus), a purple wildflower that's found predominantly in Medina County. Now a candidate for endangered species status, it is one plant that could benefit from land development.

As ranches are divided into 2- and 3-acre tracts for homes, flowers cultivated from collected seeds could flourish where the plants are less likely to be browsed by deer and cattle. "I can't imagine that the people who live there wouldn't like to have those plants in their backyards," she said.

Then those homeowners might see different species of butterflies and birds drawn to the flowers, just like when the Lorax and the Swomee-Swans return to the regenerated truffula forest.