red osier vs purple osier

red osier and purple osier both are nouns.

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

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

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

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

red osier (noun)	purple osier (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
common North American shrub with reddish purple twigs and white flowers