common camas vs camass

common camas and camass both are nouns.

Word	Noun	Adjective	Verb	Adverb
common camas	Yes	No	No	No
camass	Yes	No	No	No

As nouns, camass is a hypernym of common camas; that is, camass is a word with a broader meaning than common camas:

common camas: plant having a large edible bulb and linear basal leaves and racemes of light to deep violet-blue star-shaped flowers on tall green scapes; western North America
camass: any of several plants of the genus Camassia; North and South America

Other hypernyms of common camas include camas, camash, camosh, quamash.

common camas (noun)	camass (noun)
plant having a large edible bulb and linear basal leaves and racemes of light to deep violet-blue star-shaped flowers on tall green scapes; western North America	any of several plants of the genus Camassia; North and South America