purple orchis vs purple-hooded orchis

purple orchis and purple-hooded orchis both are nouns.

Word	Noun	Adjective	Verb	Adverb
purple orchis	Yes	No	No	No
purple-hooded orchis	Yes	No	No	No

As nouns, purple orchis and purple-hooded orchis are synonyms defined as:

purple orchis and purple-hooded orchis: North American orchid having a spike of violet-purple flowers mixed with white; sepals and petals form a hood

Other synonyms of purple orchis include Orchis spectabilis, showy orchis.

purple orchis (noun)	purple-hooded orchis (noun)
North American orchid having a spike of violet-purple flowers mixed with white; sepals and petals form a hood	North American orchid having a spike of violet-purple flowers mixed with white; sepals and petals form a hood