The Crack Willow is a medium-sized tree which is rare in the Donau-Auen National Park but found in the softwood riparian forests of the Danube wetlands and in damp meadows. It is called "crack" willow because its twigs break off easily at the base. Is more likely to occur as hybrid form with the White Willow. Thrives on deep soils with a good supply of moisture.
Description
This medium-sized willow normally grows to 15m height (more rarely to 20m) and has a trunk diameter of up to 1m. It often has multiple stems, like a shrub. It has upward-forking branches and a broad crown which may narrow at the top. The glossy yellow or light-brown twigs are completely hairless and often very long; as young branches they may be easily snapped at the base. Older twigs stand at more or less right angles. Bark is smooth and greyish-yellow in the beginning but later turns brighter green and develops long furrows on the trunk(s) before finally turning greyish-brown with x-shaped bands which tend to peel. Leaves are up to 16cm long, finely toothed and lancet-shaped, completely hairless and dark green glossy above. Species is dioecious; flowers from March to May.
Distribution
Its original and natural range is difficult to determine today due to frequent planting. The current range extends from the Black Forest east to Russia and north to the middle of Sweden; to the Pyrenees, the northern Apennines and the Balkans. In Austria the species is sporadic to moderately common, but rarer in the National Park.
Endangerment and Conservation Status
Regionally vulnerable in Austria, in particular in eastern Lower Austria (National Park!), northern Burgenland, and in the western Alps.
Ecological Characteristics
The Crack Willow may be found along the banks of creeks and rivers in both lowlands and sub-Alpine mountain ranges. Along with the ash and the alder, it is a component of fluvial forests and patches of wetlands. It thrives on extremely moist, deep soils, growing both in damp meadows as in soils in periodically flooded areas which are rich in nutrients, gravel and sand; or in wetlands regosol.
Special Characteristics
Frequently cultivated, the Crack Willow is used in a similar manner as the White Willow. Its pale reddish timber is tough yet light and very abrasion-resistant. It is one of the most important native willow species for forestry and as pollarded willow it yields materials used in weaving and basket-making. The pure species is actually quite rare; the Salix x rubens, the hybrid version of Salix alba and Salix fragilis, is more common.