Hercules'-club vs Hercules-club

Hercules'-club and Hercules-club both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hercules'-club	Yes	No	No	No
Hercules-club	Yes	No	No	No

As nouns, Hercules'-club and Hercules-club are synonyms defined as:

Hercules'-club and Hercules-club: densely spiny ornamental of southeastern United States and West Indies

Other synonyms of Hercules'-club include Hercules'-clubs, Zanthoxylum clava-herculis.

Hercules'-club (noun)	Hercules-club (noun)
densely spiny ornamental of southeastern United States and West Indies	densely spiny ornamental of southeastern United States and West Indies
small deciduous clump-forming tree or shrub of eastern United States