S'Ozzastru

Italy's oldest living tree has an age nobody can pin down within fifteen centuries. S'Ozzastru is a wild olive at Santu Baltolu di Carana, outside Luras in the granite hills of Gallura, and Sardinians call it su babbu mannu, the great father, or the patriarch of all wild olives. The University of Sassari puts it between 2,500 and 4,000 years old. The site that manages it says 3,000 to 4,000. The Piedmontese botanist Bruno Peyronel once suggested more than 5,000, a figure that comes with no scientific data behind it and which he applied to other trees just as freely. All of them are estimates, because an ancient olive hollows out and loses the heartwood any ring count would need, and this trunk is hollow. The measurements are firmer, and they are what makes the visit. The trunk runs 11.5 metres around, the tree stands 14 metres tall and the crown spreads about 21 metres, which is a wild olive behaving like an oak. Sardinia declared it a national natural monument in 1991. It is not a tree you stumble on. The grove is a managed site now, with a ticket office, a path and a guide, open from April to early November, and a second ancient olivastro stands a few metres along the same walk.