These prickly bushes are distinguished in their floral characters from allied genera by having a coloured bipartite calyx with the upper lobe of two teeth and the lower of three minute teeth. The spines of these shrubs are transformed leaves. The etymology of the name has not been satisfactorily explained.

1. U. Europaus. Furze, Gorse, or Whin. - The double variety of this plant is one of the most beautiful yellow-flowered shrubs we have, especially for planting in soil where little else would thrive. The Irish Furze (U. strictus) is an erect, more slender, less rigid form of this species.

2. U. nanus. - Another indigenous species, of very dwarf habit, flowering in Summer and Autumn. The bracts at the base of the calyx are very minute in this species compared with the preceding.

3. U. Hispanicus. - A dense dwarf spreading bush in which the branches and pliable spines are very long and slender. The yellow flowers are produced very freely in Spring.