Salix sepulcralis group Salix sepulcralis group The "Salix sepulcralis" group is a cultivar group containing all cultivars of hybrids between "Salix alba" and "Salix babylonica". The "sepulcralis" or × "sepulcralis" trees are sometimes referred to as white weeping willow or glaucous weeping willow in reference to the mixed appearance from the parent species. It was first described by L. Simonkai in 1890 from trees growing in Romania. The group contains both weeping and nonweeping cultivars, though the best-known of its cultivars is 'Chrysocoma', the most widely grown weeping tree.. Some of the cultivars are hybrids of "S. babylonica" var. "matsudana" 'Tortuosa' and have
Salix fragilis also spreads by root suckers, expanding into pure 'groves'. "Salix fragilis" is cultivated as a fast-growing ornamental tree. The cultivar "Salix fragilis" 'Russelliana' (syn. "S. fragilis" var. "russelliana" (Sm.) Koch) is by far the most common clone of crack willow in Great Britain and Ireland, very easily propagated by cuttings. It is a vigorous tree commonly reaching tall, with leaves up to 15 cm long. It is a female clone. "S. fragilis" has escaped cultivation to become an invasive species in various parts of the world, including: New Zealand; the upper half of the United States; and South Africa. In