cranesbill vs crane's bill

cranesbill and crane's bill both are nouns.

Word	Noun	Adjective	Verb	Adverb
cranesbill	Yes	No	No	No
crane's bill	Yes	No	No	No

As nouns, cranesbill and crane's bill are synonyms defined as:

cranesbill and crane's bill: any of numerous geraniums of the genus Geranium

cranesbill (noun)	crane's bill (noun)
any of numerous geraniums of the genus Geranium	any of numerous geraniums of the genus Geranium