HEATH, the English form of a name given in most Teutonic dialects to the common ling or heather (Callum vulgaris), but now applied to all species of Erica, an extensive genus of monopet alous plants, belonging to the family Ericaceae. The heaths are evergreen shrubs, with small narrow leaves, in whorls usually set rather thickly on the shoots ; the persistent flowers have 4 sepals, and a 4-cleft campanulate or tubular corolla, in many species more or less ventricose or inflated; the dry capsule is 4-celled, and opens, in the true Ericae, in 4 segments, to the middle of which the partitions adhere, though in the ling the valves separate at the dissepi ments. The plants are mostly of low growth, but several Afri can kinds reach the size of large bushes, and a common South European species, E. arborea, occasionally attains almost the aspect and dimensions of a tree.
One of the best known and most interesting of the family is the common heath, heather or ling, Callum vulgaris, placed by most botanists in a separate genus on account of the peculiar dehiscence of the fruit, and from the coloured calyx, which ex tends beyond the corolla, having a whorl of sepal-like bracts be neath. This shrub derives some economic importance from its forming the chief vegetation on many of those extensive wastes that occupy so large a portion of the more sterile lands of northern and western Europe, the usually desolate appearance of which is enlivened in the latter part of summer by its abundant pink blossoms. When growing erect to the height of 3 ft. or more, as it often does in sheltered places, its purple stems, close-leaved green shoots and feathery spikes of bell-shaped flowers render it one of the hand somest of the heaths ; but on the bleaker elevations and more arid slopes it frequently rises only a few inches above the ground. In all moorland countries the ling is applied to many rural purposes; the larger stems are made into brooms, the shorter tied up into bundles that serve as brushes, while the long trailing shoots are woven into baskets. Pared up with the peat about its roots it forms a good fuel, often the only one obtainable on the drier moors.
The shielings of the Scottish Highlanders were formerly con structed of heath stems, cemented together with peat-mud, worked into a kind of mortar with dry grass or straw; hovels and sheds for temporary purposes are still sometimes built in a similar way, and roofed in with ling. Laid on the ground, with the flowers above, it forms a soft springy bed, the luxurious couch of the ancient Gael. The young juicy shoots and the seeds, which remain long in the capsules, furnish the red grouse of Scotland with the larger portion of its sustenance ; the ripe seeds are eaten by many birds. The tops of the ling afford a considerable part of the winter fodder of the hill flocks, and are popularly supposed to communi cate the fine flavour to Welsh and Highland mutton, but sheep seldom crop heather while the mountain grasses and rushes are sweet and accessible. Ling has been suggested as a material for paper, but the stems are hardly sufficiently fibrous for that pur pose. The purple or fine-leaved heath, E. cinerea, one of the most beautiful of the genus, abounds on the lower moors and commons of Great Britain and western Europe, in such situations being sometimes more prevalent than the ling. The flowers of both these species yield much honey.
The genus contains about 500 known species, by far the greater part being indigenous to the western districts of South Africa, but it is also a characteristic genus of the Mediterranean re gion, while several species extend into northern Europe. No species is native in America, but ling occurs as an introduced plant on the Atlantic side from Newfoundland to New Jersey. Five species occur in Britain: E. cinerea, E. Tetralix (cross-leaved heath), both abundant on heaths and commons, E. vagans, Cor nish heath, found only in West Cornwall, E. ciliaris in the west of England and Ireland and E. mediterranea in Ireland. 'The last three are south-west European species which reach the northern limit of their distribution in the west of England and Ireland. E. scoparia is a common heath in the centre of France and elsewhere in the Mediterranean region, forming a spreading bush several feet high. It is known as bruyere, and its stout under ground rootstocks yield the briarwood used for pipes.