purple-hooded orchis vs purple orchis

purple-hooded orchis and purple orchis both are nouns.

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

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

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

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

purple-hooded orchis (noun)	purple 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