Ferns in the heart of the Laurisylve de La Palma, in the Canaries. Macaronesian laurels are relics of a type of humid subtropical vegetation that originally covered most of the Mediterranean Basin and Macaronesia when the region's climate was warmer and wetter, during much of the Tertiary era . They are present in very humid areas subject to trade winds, causing a "horizontal rain" of nearly 1500 mm / year and are dominated by lauraceae, ferns and mosses.