pistil vs simple pistil

pistil and simple pistil both are nouns.

Word	Noun	Adjective	Verb	Adverb
pistil	Yes	No	No	No
simple pistil	Yes	No	No	No

As nouns, simple pistil is a hyponym of pistil; that is, simple pistil is a word with a more specific, narrower meaning than pistil:

pistil: the female ovule-bearing part of a flower composed of ovary and style and stigma
simple pistil: consists of one carpel

Other hyponyms of pistil include compound pistil, pistillode, carpel.

pistil (noun)	simple pistil (noun)
the female ovule-bearing part of a flower composed of ovary and style and stigma	consists of one carpel