genus Tithonia vs family Compositae

genus Tithonia and family Compositae both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Tithonia	Yes	No	No	No
family Compositae	Yes	No	No	No

genus Tithonia (noun)	family Compositae (noun)
genus of robust herbs of Mexico and Central America: Mexican sunflower	plants with heads composed of many florets: aster, daisy, dandelion, goldenrod, marigold, lettuces, ragweed, sunflower, thistle, zinnia