A shrub of bushy habit, or in favourable localities a tree over 20 ft high, with a distinct trunk; young wood very hairy, the hairs branched. Leaves very densely packed in whorls of threes, 1⁄8 to 1⁄4 in. long, glabrous, linear, grooved beneath. Flowers very fragrant, borne in great profusion in March and April, and usually clustered near the end of short twigs that clothe the shoots of the preceding year, the whole making a slender panicle up to 11⁄2 ft in length. Corolla globular, 1⁄8 in. long, almost white; sepals ovate, not half as long as the corolla; stigma much flattened, white; flower-stalk 1⁄8 in. long, smooth.
Native of S. Europe, N. Africa and northern Asia Minor as far as Lazistan and the foothills of the W. Caucasus; also in Abyssinia and on many of the higher mountains of eastern and central Africa (including Mt Kilimanjaro); introduced in 1658. This fine heath is not seen at its best near London, although it grows 8 to 10 ft high there. Ultimately, however, there comes a frost that kills it. In the Isle of Wight there is, or used to be, a tree in the gardens of Steephill Castle, Ventnor, over 20 ft high, with a trunk 21⁄2 ft in girth near the ground. Even on the Dalmatian islands, where I have seen this heath wild, these dimensions are not exceeded. It appears to be able to withstand about 20° of frost with impunity, if it be of only one or two nights’ duration. The stems are very brittle and easily broken by heavy snow. In former times the wood was largely used at Cannes for turning and making into ‘briar-root’ tobacco pipes – a corruption of the French ‘bruyère’. It was once abundant along the coast from Marseilles to Genoa. The flowers, whose odour is like that of honey, remain, after fading, on the plants till June.
var. alpina Dieck – A very distinct and valuable form of tree heath. It was introduced to Kew in 1899, and has proved to be a very hardy and handsome evergreen, and has never suffered in the least by any frost experienced since that date. In the trying winter of 1908-9 even the smallest twigs were uninjured, preserving a peculiarly fresh and vivid green all the time. In more recent cold winters it has again proved to be somewhat more hardy than the type. It is a sturdy bush, stiffer and more erect in its growth than 23. arborea. The young wood has the same mossy apperanace, due to the abundance of branched hairs. The flowers are not freely borne whilst the plant is young, but afterwards they appear crowded in stiff, pyramidal panicles 1 ft or more long. They are rather dull white, but the beauty of the plant is as much in the rich cheerful green of the plumose branches all through the winter. It is now 8 to 10 ft high and 24 ft across at Kew. It was found in the mountains near Cuenca, in Spain, at over 4,500 ft.
Precisely where Dieck found the plants it is impossible to say, but according to his account it was in a wild and inaccessible part of the interior of Cuenca province, at the headwaters of the rivers Tagus and Jucar (hence probably in the mountains immediately to the north or north-east of the town of Cuenca). They grew in immense quantities at the tree-line. At the time of his visit (1892), the region where the plants were found was dominated by the all-powerful bandit Don Antonio de Torriz, and only by his favour was Dieck able to enter it.