dogtooth violet vs dog's-tooth violet

dogtooth violet and dog's-tooth violet both are nouns.

Word	Noun	Adjective	Verb	Adverb
dogtooth violet	Yes	No	No	No
dog's-tooth violet	Yes	No	No	No

As nouns, dogtooth violet and dog's-tooth violet are synonyms defined as:

dogtooth violet and dog's-tooth violet: perennial woodland spring-flowering plant; widely cultivated

Other synonyms of dogtooth violet include dogtooth.

dogtooth violet (noun)	dog's-tooth violet (noun)
perennial woodland spring-flowering plant; widely cultivated	perennial woodland spring-flowering plant; widely cultivated