KULA, Maui — A forest fire that has burned 250 acres in the Kula State Forest Reserve also is threatening four species of rare plants, a state wildlife biologist said.

The fire was reported Wednesday afternoon in the dense pine forest at the 6,500- to 7,000-foot elevation. No homes are in danger, but Fern Duvall of the state Department of Land and Natural Resources said that if the blaze continues to spread, it could destroy four Sanicula sandwicensis plants that were just discovered on Jan. 2 in the 5,000-acre Kula forest reserve.

The plant, also known as snakeroot, is a member of the parsley family; 12 other specimens are known to exist in nearby Haleakala Crater. Other endangered plants at risk from the fire are the Diellia erecta, or palapalai lau li'i, a type of fern; the Geranium arboreum, or nohoanu, a native red-flowering plant that grows only at high altitudes; and the Dubautia platyphylla, a kind of na'ena'e plant in the aster family that is found only on Haleakala.

The cause of the fire was not known. It is located on Waiohuli Trail about three miles from the Polipoli State Park cabin and camping area. Because the blaze is close to the access road to the camping grounds, the Department of Land and Natural Resources has closed the park.

Shifting winds yesterday morning funneled smoke from the fire up the ridge of Haleakala and over the summit, forcing closure of Haleakala National Park's visitor center at the summit. Smoke enveloped the backcountry and crater wilderness, and visibility was less than 100 feet, according to park employee Mike Townsend.

"It's nasty up there right now. The smoke is very caustic," Townsend said yesterday.

The visitor center was expected to reopen at 7:30 a.m. today.

The forest fire is inaccessible to ground crews, causing firefighters to focus on containing the blaze, according to Maui Fire Chief Carl Kaupalolo.

Yesterday, state forestry crews worked with county and National Park Service firefighters, while three helicopters conducted water drops, although officials said heavy cloud cover hampered aerial operations. Bulldozers and water tankers from the county and private companies assisted.

The fire was 60 percent contained as of yesterday afternoon, but for safety reasons the fire containment effort was suspended overnight. Crews are expecting to continue working into the weekend, officials said.

DLNR said campers with permits to use Polipoli State Park will be accommodated at a later time, or they can request a refund of permit fees or request a permit for the Wai'anapanapa State Park cabins in Hana.

Reach Christie Wilson at cwilson@honoluluadvertiser.com.