Perhaps overlooked as a small, bushy, suckering tree, Sea Buckthorn fills an important ecological niche, stabilising coastal dunes while its nitrogen-fixing root nodules improve fertility, helping species such as Hawthorn and Elder colonise barren soils. In Britain it is the only native tree with a recognised dune-scrub habitat, typically growing with marram grass, and though specialised for the coast it can grow on almost any site and soil.

Native across Europe, from southern Spain to inside the Arctic Circle in Scandinavia, and eastwards through Central Asia to China. Native in Britain, probably only the east coast of England, and elsewhere a widely planted neophyte.

Dioecious, wind-pollinated, although ladybirds and thrips feed on pollen grains. Fruit a drupe, its seeds distributed in the faeces of frugivorous birds. Plants also spread by root suckers and rhizomes, forming dense thickets.

Small (6m), short-trunked and usually leaning, reaching 10-12m among taller trees. Bushy and spiny, especially at the tips, robustly twiggy and dark in winter, with intensely silver-grey foliage. Bark and branches dark brown, rough, frequently spined. Twigs silver-scaled; buds orange, alternate. Leaves slender-lanceolate (70x7mm), dull green above, pale silver and densely scaled below, entire, almost sessile. Flowers tiny, yellow-green (March-May). Female trees bear dense clusters of fleshy orange drupes from September through winter. Oleasters differ: red, silver-marbled, less densely clustered fruit.

Thrives in almost any soil except waterlogged. Several cultivars exist, for fruit or ornament; ensure male trees are nearby for berries. 'Leikora' is a compact female with large vitamin-C-rich orange berries, 'Frugana' is almost thornless and female, and 'Hergo' is a high-yielding female whose branches often droop under fruit. It is sometimes invasive outside its natural habitat; in Ireland, though its sale is not banned, it is an offence to encourage it to grow in the wild.

Sea Buckthorn forms important coastal scrub habitat for migrant and breeding birds, including Fieldfare (Turdus pilaris) and Redwing (T. iliacus), which feast on its fruit once frost has sweetened (bletted) it. Seeds passed in bird droppings germinate at higher rates than uneaten ones, so there is a mutually beneficial relationship between bird and tree.

Generally healthy.

An attractive ornamental, for both foliage and colourful berries, and useful in coastal habitat conservation, with increasing interest in agroforestry. Its sour berries are rich in omega oils and vitamins and are sometimes harvested for jellies and syrups. It is likely to thrive with increasing drought under a warming climate.