A shrub or small tree up to 30 ft high in the wild, densely branched; young stems square, and at first slightly downy. Leaves roundish oval to ovate-oblong; 3⁄4 to 11⁄2 in. long, 1⁄4 to 3⁄4 in. wide, wedge-shaped at the base, usually notched at the apex (or the terminal leaves sometimes minutely and abruptly pointed); thick and leathery, dark glossy green above, but not so shining as in B. sempervirens, pale green beneath; stalk slightly downy, 1⁄12 in long. Flowers yellowish green, of no beauty; males shortly stalked.
Native of the Balearic Islands and the south-west of Spain. The species is easily distinguished from the common box by the duller, larger leaves, the thicker, more robust shoots, and the sturdier habit. The largest specimen I have seen in this country was at Kew, near the Temple of the Sun, and was about 24 ft high, its trunk 21⁄2 ft in girth. It grew slowly, and was probably the oldest in the country. Loudon mentioned this tree, which once grew on the wall of a house, as being 13 ft high in 1836. Aiton gives 1780 as the date of its introduction. It was blown down during a storm in March 1916, the Temple of the Sun being destroyed at the same time. In the gardens of S. Europe this box takes the place that B. sempervirens occupies here.