purple osier vs purple willow

purple osier and purple willow both are nouns.

Word	Noun	Adjective	Verb	Adverb
purple osier	Yes	No	No	No
purple willow	Yes	No	No	No

As nouns, purple osier and purple willow are synonyms defined as:

purple osier and purple willow: Eurasian osier having reddish or purple twigs and bark rich in tannin

Other synonyms of purple osier include basket willow, red osier, red willow, Salix purpurea.

purple osier (noun)	purple willow (noun)
Eurasian osier having reddish or purple twigs and bark rich in tannin	Eurasian osier having reddish or purple twigs and bark rich in tannin