Stone pine Pinus pinea

Widely known for its nuts, the stone or umbrella pine is an unusual and distinctive-looking tree. Probably only native to Spain and Portugal originally, it has been introduced to and grown successfully in locations with Mediterranean climates worldwide.

Of the dozen or so species of pine now resident in Britain, Pinus pinea is one of the most easily recognisable. Also known as the umbrella pine, it has a tall, slim trunk, relative to its height, with a spray of branches at the top, which radiate outwards just like an umbrella.

It is not known precisely when the stone pine first made an appearance in Britain as the species has been cultivated in Europe for almost 2,000 years, but the first planting at Kew was in 1846. The lifespan of pines varies depending on its environment but they have been known to live as long as 300 years. The specimen at Kew is more than 160 years old and appears to be in good shape, so only time will tell how long it survives.

The pine nuts from Pinus pinea have been eaten for thousands of years - Roman soldiers considered them to be a delicacy. Today, they are widely used in French and especially Italian cooking. For example, they are an essential component of pesto sauce, along with basil, parmesan and pecorino cheese, garlic, salt and olive oil. Further afield, pine nut coffee is popular in New Mexico in the US, while it is also featured in Middle Eastern cuisine, such as in the sweet pastry dessert baklava.

Botanically speaking, pine nuts are seeds rather than nuts and come from the cones of the stone pine. Frustratingly for the pine nut grower, the cones of this species take the longest of all pines to mature, a full three years. Seeds are then kept in their cones until they are ready for eating or roasting as they quickly turn rancid once removed.

In Britain, it is generally not warm enough for the trees to produce ripe pine nuts and is planted only as an ornamental tree.