[7] ilstri (n.) ‘willow’: A hap. leg. in Old Norse, derived from Gmc *elistria (AEW: ilstri; cf. New Norw., ModSwed. dialects ilster ‘grey willow’, Salix cinerea). Morphologically the word is a collective noun, but cf. jǫlstr f. ‘willow’ in the next line.