purple willow vs Salix purpurea

purple willow and Salix purpurea both are nouns.

Word	Noun	Adjective	Verb	Adverb
purple willow	Yes	No	No	No
Salix purpurea	Yes	No	No	No

As nouns, purple willow and Salix purpurea are synonyms defined as:

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

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

purple willow (noun)	Salix purpurea (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