Botanists say an old yew tree �C one of the world's most endangered plant species -- that grows in a nature reserve in the northwestern Shaanxi Province, is at least 500 years old.

The "king yew" that grows in a river valley in a nature reserve of Fuping county, at the foot of the Qinling Mountain Ranges, is approximately 18 meters tall and has a trunk circumference of up to 3.2 meters, according to a team of botanists with prestigious Northwest China University during a recent survey on the resources of the rare plant species in the county.

The evergreen tree on the verge of extinction rarely grows in Fuping county and an inventory by the local forestry administration show only 27 have so far been confirmed.

Wild plant experts chanced upon more than 400 of the rare trees in the eastern Jiangxi province last November, 20 of which averaged one meter in diameter, indicating a lifespan of some 600 years.

Normally it takes 250 years for yews to mature.

Chinese yew trees, having survived the Tertiary period, have elegant forms with spiral leaves and egg-shaped seeds. Materials extracted from the yews is believed to contain rich anti-cancer substance.

Source: Xinhua