It resembles the known European hybrid between a species of the section Vetrix ( S. caprea or S. cinerea ) and S. viminalis . This hybrid was recorded from SE Massachusetts under the name S. x smithiana . The characters of this tree, however, don't completely match S. x smithiana . Alternatively this could be a spontaneous hybrid between the only two willows common in the Forest: the native S. occidentalis ( S. tristis ) and introduced invasive S. atrocinerea . To test this hypothesis, one should either try to obtain an artificial cross between the two willows and compare it with the willow in question or apply molecular methods.