breakstone vs herbaceous plant

breakstone and herbaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
breakstone	Yes	No	No	No
herbaceous plant	Yes	No	No	No

As nouns, herbaceous plant is a hypernym of breakstone; that is, herbaceous plant is a word with a broader meaning than breakstone:

breakstone: any of various plants of the genus Saxifraga
herbaceous plant: a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests

Other hypernyms of breakstone include herb.

breakstone (noun)	herbaceous plant (noun)
any of various plants of the genus Saxifraga	a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests