peduncle vs flower stalk

peduncle and flower stalk both are nouns.

Word	Noun	Adjective	Verb	Adverb
peduncle	Yes	No	No	No
flower stalk	Yes	No	No	No

As nouns, flower stalk is a hypernym of peduncle; that is, flower stalk is a word with a broader meaning than peduncle:

peduncle: stalk bearing an inflorescence or solitary flower
flower stalk: erect leafless flower stalk growing directly from the ground as in a tulip

Other hypernyms of peduncle include scape.

peduncle (noun)	flower stalk (noun)
a bundle of myelinated neurons joining different parts of the brain	erect leafless flower stalk growing directly from the ground as in a tulip
stalk bearing an inflorescence or solitary flower
the thin process of tissue that attaches a polyp to the body