Just over three years old and about one metre tall, Methuselah is growing well.

"It's lovely," Dr. Sarah Sallon said of the date palm, whose parents may have provided food for the besieged Jews at Masada some 2,000 years ago.

The little tree was sprouted in 2005 from a seed recovered from Masada, where rebelling Jews committed suicide rather than surrender to Roman attackers.

Radiocarbon dating of seed fragments clinging to its root, as well as other seeds found with it that didn't sprout, indicate they were about 2,000 years old: the oldest seed known to have been sprouted and grown.

Sallon, director of the Louis L. Borick Natural Medicine Research Center at Hadassah Medical Organization in Israel, updates the saga of Methuselah in Friday's edition of the journal Science.

One thing they don't know yet is whether it's a boy or girl. Date palms differ by sex, but experts can't tell the difference until the tree is six or seven years old, Sallon said.

Prized for medicinal uses

She hopes there's a chance to use it to restore the extinct Judean date palm, once prized not only for its fruit but also for medicinal uses.

The researchers have had a look at the plant's DNA, however, and found it shares just over half its genes with modern date cultivars.

"Part of our project is to preserve ancient knowledge of how plants were used," Sallon said in a telephone interview. "To domesticate them so we have a ready source of raw material."

Her Middle Eastern Medicinal Plant Project is working to conserve and reintroduce plants to the region where they once lived.

"Many species are endangered and becoming extinct. Raising the dead is very difficult, so it's better to preserve them before they become extinct," she said.

The oldest documented seed to be grown previously was a 1,300-year-old lotus, Sallon said.