Tree heath [wood = brier-root/briar root] (Eng); brezo, brezo blanco (Spa); bruc blanc, dinada (Cat); añar-zuria, zuricacha (Baq); urce, urce branca (Glg); urze branca, quiroga (Por).
"My practice has extended recently to the Continent,” said Holmes, after a while, filling up his old brier-root pipe.
'Sherlock Holmes. The Sign of Four', Arthur Conan Doyle
The tree heath is a shrub, small tree or very branching, leafy tree. It is evergreen and can be very variable in shape. In the closed forests there are specimens as tall as 10-15 m, even up to 20 m, as seen on La Gomera. Its bark is generally brown and fibrous, and when mature it detaches in long thin strips. The young twigs are covered with unequal, whitish hairs. The leaves are simple, hairless, rigid, thin and very narrow (linear), in the form of short needles, the edges of which curve over towards the underside in such a way that they appear to have a groove on them. They measure 3-8 mm in length and 1-2 mm in width, and are arranged on the twigs in groups of 3 or 4 like the blades of a fan. The flowers are hermaphroditic, whitish or slightly pink in colour, very small (up to 3 mm in length), and with a fairly long stalk. They grow in showy terminal groups that are pyramidal in shape. They are shaped like closed, narrow bells, and when they mature the stamens remain inside. The fruits are very small capsules, not quite 2 mm in diameter, that open up into 4 parts, known as valves. They contain tiny seeds (0.5 mm) and are finely striated The tree heath can be confused with its relative Erica platycodon subsp. platycodon, but the leaves of the tree heath are narrower and more rolled, and they are arranged very closely together on the upright twigs. In addition, the flower colour distinguishes these two species as the blossom of Erica platycodon is a deep pinkish-reddish colour.
It prefers acidic soils that are fairly deep, cool and moderately moist. Often the tree heath becomes dominant and is found in extensive formations, known locally as brezales/i>, or it can be associated with the firetree (Myrica faya) in the Morella-Erica heath community. However, the tree heath also colonises degraded land in the laurel forest, and can even grow in the underbrush of mixed pine groves. It is mainly found between altitudes of 500 and 1200 m, although there are solitary specimens or small groups at very low levels (300-400 m).
The tree heath is a very widely-distributed species. It lives in the Mediterranean, the Canary Islands, Madeira, northern and eastern Africa, Asia Minor, and the Caucasus. It is one of the most common trees in the Canaries and grows on all the islands in the archipelago, although until recently it was thought to have disappeared from Fuerteventura and Lanzarote.