Gorse - Definition and Overview

Gorse (Ulex) comprises a genus of about 20 species of evergreen shrubs in the subfamily Faboideae of the pea family Fabaceae, native to western Europe and northwest Africa, with the majority of species in Iberia. Other common names for "gorse" include whin and furze.

Gorse is closely related to the brooms, and like them, has green stems and very small leaves, adaptations to dry growing conditions, but differs in its extreme spininess, with the leaves being modified into 1-4cm long spines. All the species have yellow flowers, some with a very long flowering season.

The most widely familiar species is the Common gorse (Ulex europaeus), the only species native in of most of western Europe, where it grows in sunny sites, usually on dry, sandy soils. It is also the largest species, reaching 2-3m height; this compares with typically 0.2-0.4m for Western gorse (U. gallii). This latter species is characteristic of highly exposed Atlantic coastal heathland, where a combination of wind strength and salt spray prevents larger plants from growing.

Common gorse flowers most strongly in spring, though it bears some flowers year round, hence the old country phrase: "When gorse is out of blossom, kissing's out of fashion". The flowers have a very distinctive strong coconut scent. Western gorse and Dwarf gorse differ in being almost entirely late summer flowering (August-September in Britain), and also have somewhat darker yellow flowers than Common gorse.

Gorse is a fire-climax plant, very well adapted to stand-replacing fires, being highly inflammable, and having seed pods that are to a large extent opened by fire, thus allowing rapid regeneration after fire. The burnt stumps also readily sprout new growth from the roots. Where fire is excluded, gorse soon tends to be shaded out by taller-growing trees, unless other factors like exposure also apply. Typical fire recurrence periods in gorse stands are 5-20 years.

Gorse thrives best in poor growing areas and conditions; it has been widely used for land reclamation (e.g. mine tailings), where its nitrogen-fixing capacity helps other plants establish better.

It is a valuable plant for wildlife, providing dense thorny cover ideal for protecting bird nests; in Britain and France, it is particularly noted for supporting European Stonechats and Dartford Warblers.

In many areas of North America, southern South America, Australia and New Zealand, the Common gorse, introduced as an ornamental plant, has become naturalised and an invasive weed due to its aggressive seed dispersal; it has proved very difficult to eradicate. However, in New Zealand, it has been found to form a useful nursery species for native bush regeneration. If gorse stands are left for several years, native seedlings generate in their shelter and eventually grow up through the gorse, cutting out its light and eventually replacing it.