Cogon grass can seem harmless — even beautiful — but forestry experts in South Carolina, Georgia, Florida and Alabama warn it’s a killer.

The invasive weed already has infested more than 1 million acres nationwide and experts say the Southeast’s drought makes the highly flammable intruder more threatening than ever.

Cogon grass, known for its fluffy, silvery white seed heads, has coaxed its way into gardens, forests and highway medians. Control and eradication programs are underway.

“Don’t buy it, don’t dig it up, don’t plant it and just let somebody know if you see it,” said Laurie Reid, forest health specialist for the South Carolina Forestry Commission.

Now in its flowering stage, cogon grass can burn all year. When it catches fire, experts say it burns higher and hotter than regular grass during wildfires.

It’s most flammable in colder months when it appears as a tall, thick mass of brown-colored grass. But drought conditions in the Southeast have kept the weed dry and increased its risk as a fire hazard this spring, experts say.

“I don’t think there’s anything more flammable in our environment’s landscape. I don’t know anything that burns as hot in our ecosystem as cogon grass,” said Jim Miller, a regional invasive plant scientist with the federal Agriculture Department.

A native of southeastern Asia, cogon grass was once used as packing material that arrived in Mobile, Ala., on ships in 1912. It chokes all competing vegetation — it kills off pine seedlings in forests and overtakes grazing land where most animals won’t give it a second look because of its saw-toothed leaves.

Experts believe the aggressive weed could turn the region into a grassy savannah devoid of all native species if given enough time. Ironically, forestry experts said, the grass has spread in part because it’s hitched rides on equipment used to fight forest fires.

“It’s actually got to epidemic proportions,” said Ed Brown, a spokesman for the Mississippi Forestry Commission. “I call it a super weed. I have seen it grow on some of the driest sites that wouldn’t hardly grow anything and I’ve seen it growing down the edge of water. I’ve actually seen it taking over a patch of kudzu.”

Cogon grass — sometimes spelled cogongrass — is on every continent except Antarctica and inhabits around 1.2 billion acres worldwide. Asia has lost about 500 million acres to the weed, and it continues to spread to an additional 370,000 acres each year, experts say.

“It’s definitely a worldwide problem and now we are a part of that worldwide problem in the Southeast because we have failed to confront it,” Miller said.

Florida now has over 1 million acres and Miller said he’s heard reports of cogon grass causing intense home fires there. Alabama has 60,000 acres of it; South Carolina only 10 acres, so far, according to estimates done by the USDA and Clemson University.

States, with the help of a federal grant awarded last year, are starting to coordinate efforts to study, survey and control the spread of cogon grass.

Clemson University scientists plan to survey more than half of South Carolina next month. Because there are only small patches of it here, including in a national forest, experts think they can stomp out the weed. “We have a real chance of eradicating it if we stay on top of it,” said Steve Compton, a regulatory agent with the Clemson University Department of Plant Industry.

Alabama has formed a cogon grass task force. Officials there hope to determine where in the state cogon grass can be wiped out — and where it can only be contained.

“We are trying to figure out where we can kind of draw a line in south Alabama and say, ’On this side of the line there’s not a lot we can do. But on the other side of the line we are going to do everything we can do eradicate it,”’ said Forestry Management Division Director John Pirtle.

On the Net:

Cogon grass: http://www.cogongrass.org