gravelweed vs crownbeard

gravelweed and crownbeard both are nouns.

Word	Noun	Adjective	Verb	Adverb
gravelweed	Yes	No	No	No
crownbeard	Yes	No	No	No

As nouns, crownbeard is a hypernym of gravelweed; that is, crownbeard is a word with a broader meaning than gravelweed:

gravelweed: perennial herb with yellow flowers; southern and south central United States
crownbeard: any plant of the genus Verbesina having clustered white or yellow flower heads

Other hypernyms of gravelweed include crown-beard, crown beard.

gravelweed (noun)	crownbeard (noun)
perennial herb with yellow flowers; southern and south central United States	any plant of the genus Verbesina having clustered white or yellow flower heads