gorse, tojo

Description:

Gorse is an evergreen shrub in the family Fabaceae, native to western Europe from the northerly point of the United Kingdom south to Portugal, and from the westerly point of the Republic of Ireland east to Galicia in Poland and Ukraine. It grows to 2–3 metres tall. The young stems are green, with the shoots and leaves modified into green spines, 1–3 centimetres long. Young seedlings produce normal leaves for the first few months; these are trifoliate, resembling a small clover leaf. The flowers are yellow, 1–2 centimetres long, with the typical pea-flower structure; they are produced throughout the year, but mainly in the early spring. The fruit is a legume (pod) 2 centimetres long, dark purplish-brown, partly enclosed by the pale brown remnants of the flower; the pod contains 2-3 small blackish seeds, which are released when the pod splits open in hot weather. Like many species of gorse, it is often a fire-climax plant, which readily catches fire but re-grows from the roots after the fire; the seeds are also adapted to germinate after slight scorching by fire.

Habitat:

The species has been introduced to other areas of Europe, and also to the Americas, New Zealand and Australia, where it is often considered a weed and is a serious problem invasive species in some areas (notably the western United States, Chile and New Zealand). It was introduced to New Zealand from Scotland as a type of hedge, but became a major blight to farmers as the climate suited its growth better than its native habitat and many of its natural predators were absent. Biological pest control is used on this plant in many areas. The gorse spider mite (Tetranychus lintearius) and the gorse seed weevil (Exapion ulicis) reduce the spread of the plant.

Notes:

Bruised gorse was used in some areas for feeding to horses and other livestock. Lectin extracted from seeds of this species binds to, is remarkably specific for, and is the standard method for identification of H-substance (absent in the hh antigen system) on human red blood cells. The vast majority of humans express H-substance, which is the basis for the ABO blood group system, but a few rare individuals ("Bombay phenotype") do not—and a chemical isolated from Ulex europaeus is used to identify these individuals.