Culver's physic vs Culvers physic

Culver's physic and Culvers physic both are nouns.

Word	Noun	Adjective	Verb	Adverb
Culver's physic	Yes	No	No	No
Culvers physic	Yes	No	No	No

As nouns, Culver's physic and Culvers physic are synonyms defined as:

Culver's physic and Culvers physic: a tall perennial herb having spikes of small white or purple flowers; common in eastern North America

Other synonyms of Culver's physic include Culver's root, Culvers root, Veronicastrum virginicum, whorlywort.

Culver's physic (noun)	Culvers physic (noun)
a tall perennial herb having spikes of small white or purple flowers; common in eastern North America	a tall perennial herb having spikes of small white or purple flowers; common in eastern North America