Any of several tropical and subtropical marsh plants of the family Onagraceae (evening primroses); now especially Ludwigia peruviana of South America, which has conspicuous yellow primrose-like flowers.
Origin
Mid 18th century; earliest use found in Patrick Browne (c1720–1790), physician and botanist.
Definition of primrose willow in US English:
primrose willow
noun
US
Any of several tropical and subtropical marsh plants of the family Onagraceae (evening primroses); now especially Ludwigia peruviana of South America, which has conspicuous yellow primrose-like flowers.
Origin
Mid 18th century; earliest use found in Patrick Browne (c1720–1790), physician and botanist.