Disease killing S.C., Fla. state tree

The sabal palmetto, South Carolina's state tree, is under attack by a microscopic killer that has scientists stumped.

An unknown but growing number of sabal palms have died from a mysterious disease that researchers are struggling to identify. Even after they pinpoint the disease — and that could take years — researchers will have to learn what insect spreads it. The disease will be tough to stop.

Sabal palms, also known cabbage palms, can grow to 50 feet. In the U.S., they can be found from the Florida Keys to parts of North Carolina and can grow in marshes, woodlands or along the coastline. The palm, which is also Florida's state tree, is featured on South Carolina's flag and was designated the state tree in 1939.

Tim Schubert, an administrator and pathologist in Florida's Division of Plant Industry, said that it's impossible to say what the disease's eventual effect on the sabal palms will be but that “it's not going to be good.”

“There's going to be fewer palms. They may present a less attractive tree in nature because of this new disease showing up,” he said.

The disease destroys the sabal palm and its other victims, which include Canary Island date palms and queen palms, from within. It's a tough diagnosis, plant pathologist Monica Elliott said, often confused with nutrient deficiencies or excessive trimming. First to go are the lower leaves in the tree's canopy, followed by a dead spear leaf. Finally, the palm's canopy collapses.

It's a phytoplasma disease, which means it is a very small bacterium that doesn't have a cell wall. And it can only be transmitted through a plant's phloem, a type of transport tissue similar to veins in a human. The disease has likely found its way to sabal palms' phloem by either a tree- or leaf-hopping insect.