Crack willow, brittle willow (Eng); mimbrera, sauce (Spa); vimetera (Cat); zume hauskorra (Baq); salgueira (Glg); salgueiro-frágil (Por).
"I slept in the dark eternity / sweet sleep, tired forehead / resting on a willow springing / solitary on the stream bank."
‘La corona de oro’, Gustavo Adolfo Bécquer
This willow can be up to 20 m tall, has an upright trunk, grey, fissured bark, and brittle twigs in older specimens, as its name suggests. The leaves are deciduous, simple, alternate, long and lanceolate, 5-16 cm long and 1-3 cm wide, with a finely serrated margin and a greyish-green underside. Adult leaves are hairless on both sides and narrow to an oblique point, characteristics that differentiate this species from Salix canariensis . This is a dioecious plant where the male and female blossom appear on distinct individuals. Individually, the flowers are inconspicuous and appear in spring grouped into long hanging filaments known as catkins. The fruits are capsules that, when ripe, open into two parts, known as valves, releasing numerous seeds wrapped in a cottony down that aids their dispersal by the wind.
The crack willow grows in zones with shallow groundwater, associated with water courses or bodies of water. The ease with which its branches break, sometimes with the mere blowing of the wind, means that a good number of them fall into suitable places to root and form a new plant. This willow alternates this vegetative reproduction with the formation of seeds. Additionally, the tangled matt formed by the roots of willows in general, along with many riparian trees and shrubs, helps stabilise riverbanks and reduce the risk of floods. Like its Canarian relative (Salix canariensis), the crack willow always grows near water ditches, headwaters, and on banks next to running water, mainly on the midslopes, or medianías, or occasionally in the lower parts of the summit zones in the Canaries.
The crack willow is found across almost all of Europe and a large part of southwestern Asia, and it is naturalised in many places. In the Canary Islands, this plant can be found established in the wild on El Hierro, La Gomera, Tenerife and Gran Canaria.