tortoise plant vs elephant's-foot

tortoise plant and elephant's-foot both are nouns.

Word	Noun	Adjective	Verb	Adverb
tortoise plant	Yes	No	No	No
elephant's-foot	Yes	No	No	No

As nouns, tortoise plant and elephant's-foot are synonyms defined as:

tortoise plant and elephant's-foot: South African vine having a massive rootstock covered with deeply fissured bark

Other synonyms of tortoise plant include Dioscorea elephantipes, Hottentot's bread vine, Hottentot bread vine.

tortoise plant (noun)	elephant's-foot (noun)
South African vine having a massive rootstock covered with deeply fissured bark	any plant of the genus Elephantopus having heads of blue or purple flowers; America
	South African vine having a massive rootstock covered with deeply fissured bark