Silphium vs asterid dicot genus

Silphium and asterid dicot genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Silphium	Yes	No	No	No
asterid dicot genus	Yes	No	No	No

As nouns, asterid dicot genus is a hypernym of Silphium; that is, asterid dicot genus is a word with a broader meaning than Silphium:

Silphium: tall North American perennial herbs
asterid dicot genus: genus of more or less advanced dicotyledonous herbs and some trees and shrubs

Silphium (noun)	asterid dicot genus (noun)
tall North American perennial herbs	genus of more or less advanced dicotyledonous herbs and some trees and shrubs