pileus vs plant structure

pileus and plant structure both are nouns.

Word	Noun	Adjective	Verb	Adverb
pileus	Yes	No	No	No
plant structure	Yes	No	No	No

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

pileus: a fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroom
plant structure: any part of a plant or fungus

Other hypernyms of pileus include plant part.

pileus (noun)	plant structure (noun)
a fruiting structure resembling an umbrella or a cone that forms the top of a stalked fleshy fungus such as a mushroom	any part of a plant or fungus