live-forever vs sedum

live-forever and sedum both are nouns.

Word	Noun	Adjective	Verb	Adverb
live-forever	Yes	No	No	No
sedum	Yes	No	No	No

As nouns, sedum is a hypernym of live-forever; that is, sedum is a word with a broader meaning than live-forever:

live-forever: perennial northern temperate plant with toothed leaves and heads of small purplish-white flowers
sedum: any of various plants of the genus Sedum

live-forever (noun)	sedum (noun)
perennial northern temperate plant with toothed leaves and heads of small purplish-white flowers	any of various plants of the genus Sedum