Hiker May Have Put Prehistoric Grove at Risk

The only known wild grove of a tree species dating back 200 million years has been endangered by a disease possibly introduced by a hiker who found the grove in Australia, a government official said Monday.

The Wollemi pine -- dating from the Jurassic period and often described as a living fossil -- was thought to be extinct until 1994, when a park ranger stumbled upon a stand of fewer than 100 trees in a remote gorge in Wollemi National Park, 120 miles west of Sydney.

Although authorized visitors must undergo infection control procedures, two trees have been infected by the fungus-like disease Phytophthora cinnamomi.