A water milfoil, Myriophyllum aquaticum, with whorls of green feather-like foliage, native to South America and now grown and naturalized widely elsewhere.
Origin
Late 19th century; earliest use found in Garden & Forest.
Definition of parrot's feather in US English:
parrot's feather
(also parrotfeather, parrot feather)
noun
A water milfoil, Myriophyllum aquaticum, with whorls of green feather-like foliage, native to South America and now grown and naturalized widely elsewhere.
Origin
Late 19th century; earliest use found in Garden & Forest.