Geranium richardsonii vs Richardson's geranium

Geranium richardsonii and Richardson's geranium both are nouns.

Word	Noun	Adjective	Verb	Adverb
Geranium richardsonii	Yes	No	No	No
Richardson's geranium	Yes	No	No	No

As nouns, Geranium richardsonii and Richardson's geranium are synonyms defined as:

Geranium richardsonii and Richardson's geranium: geranium of western North America having branched clusters of white or pale pink flowers

Geranium richardsonii (noun)	Richardson's geranium (noun)
geranium of western North America having branched clusters of white or pale pink flowers	geranium of western North America having branched clusters of white or pale pink flowers