To protect the Cape Sable thoroughwart, an endangered plant described by supporters as "a showy but dainty little herb," the federal government will protect 4,802 acres of land in the Florida Keys as critical habitat for the species.
The vast majority of the undeveloped habitat, more than 85 percent, is owned by the state or federal governments as park or conservation land.
Rules intended to safeguard the habitat of the Cape Sable thoroughwart ("Chromolaena frustrata") also apply to about 703 acres in private ownership on six Keys islands.
"The quality and quantity of the habitat will buy the plant time as the surrounding landscape changes or is lost to the sea," said Jaclyn Lopez, a Florida attorney for the Center for Biological Diversity, an environmental group.
The designation written by the U.S. Fish and Wildlife Service to settle a lawsuit filed by the Center for Biological Diversity becomes effective Feb. 7.
"For private landowners, it should have little effect," Fish and Wildlife spokesman Ken Warren said Tuesday.
"If you undertake a project that involves federal funding or a federal study, it possibly could affect you," Warren said. "Otherwise, it won't."
Previous critical-habitat designations in the Keys have limited flood-insurance provided through the Federal Emergency Management Agency, but those were mostly lifted by a revised 2010 ruling.
Whether the new designation for the thoroughwart might extend to flood-insurance coverage could not be determined by FWS at press time.
Overall, the designation covers 10,968 acres in South Florida, of which 6,116 are part of Everglades National Park.
"The plant once occurred in Monroe County and along Florida Bay in Everglades National Park," according to the Center for Biological Diversity. "Now no more than a few thousand plants survive on the park's southern tip and on a handful of Keys."
The state's Division of Plant Industry, part of the Florida Department of Agriculture and Consumer Services, endorsed the critical-habitat designation.
A 2010 survey found the Cape Sable thoroughwart -- found nowhere in the United States outside of Monroe and Miami-Dade counties -- had "a total number of individuals less than 1,000," wrote division Director Richard Gaskalla.
The thoroughwart has "lance-shaped, aromatic leaves, and beautiful little lavender-to-blue flowers that attract bees, butterflies and birds," says the Center for Biological Diversity.
"The Cape Sable thoroughwort is a flowering perennial herb found in rockland hammocks, coastal hardwood hammocks, buttonwood forests, coastal rock barrens, and coastal berms," according to FWS. "The decline of the Cape Sable thoroughwort is primarily the result of habitat loss from commercial and residential development, sea level rise, storms, competition from nonnative plants, predation by nonnative herbivores, and wildfires."
Key Largo accounts for 3,431 of the local acres under critical-habitat protection, mostly in state parks and federal wildlife refuges. Private owners hold 457 acres of the critical habitat on Key Largo.
Big Pine Key has 94 acres of thoroughwart habitat in private ownership, and 686 acres in federal ownership.
All 28 habitat acres on Big Munson Island are privately owned.
Other islands with Cape Sable thoroughwart habitat are Upper Matecumbe Key (69 acres, 45 privately owned), Lower Matecumbe Key (44 acres, 22 private) and Long Key (151 acres, 57 private).
The state or federal government owns all designated habitat on Boca Grande and Lignumvitae Key.