Several 365-year-old seeds that sank with the Spanish treasure galleon Atocha have been brought to the surface and have sprouted, according to an archeologist working on the wreck.

It is an "extremely unusual occurrence for seeds that old to sprout and almost unheard of for seeds to be brought out of the sea and still sprout, said Dr. David Hall of the University of Florida.

Apparently the seeds -- of a variety of weed -- were preserved under dried, caked-on mud that was packed under four heavy planks of the hull of the wreck.

Corey Malcom, an archeologist working on contract with the Mel Fisher Maritime Heritage Society on the wreck, said that he recovered grape seeds, olive and apricot pits, and many other, unidentified seeds from the wreck, which lay under 55 feet of water in the Caribbean near Key West, Fla.

Malcom said that when he sifted the seeds out of the mud and put them in fresh water, one of them sprouted. Eventually four of the seeds sprouted.

He planted all four sprouts. Two of them are still living. They have been tentatively identified as plants of a variety of weed called beggar's tick, or Bidens Alba. The weed is very common in the Caribbean. Florida's Hall made the preliminary identification from photographs, but said he won't be certain until the tiny leaves on the two-inch seedling grow out and the plants flower.

There have been other reports of seeds sprouting after hundreds or even thousands of years, said Dr. Raymond B. Taylorson, a plant physiologist at the Department of Agricuture's Beltsville research station.

Seeds commonly survive for five to 10 years under the right conditions, he said. Some with exceptionally tough outer shells can survive much longer than that.

Seeds of water lotus plants have germinated after more than a thousand years of burial in the mud, he said. A Canadian researcher has reported that he found seeds of the Arctic flower Lupines arcticus that sprouted and grew healthy plants after about 10,000 years of preservation in frozen silt.

But Taylorson said scientists would have to investigate thoroughly the germination of the seeds from the Spanish galleon to verify the report. It is rare for seeds to sprout after being immersed in salt water, which kills seeds that don't have exceptionally water-tight coats.

The Atocha sank in a hurricane 35 miles from Key West in 1622, and its treasure -- more than $130 million in gold, silver and emeralds -- was recovered in 1985 by treasure-hunter Mel Fisher and his salvage team.