family Compositae vs genus Xanthium

family Compositae and genus Xanthium both are nouns.

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

family Compositae (noun)	genus Xanthium (noun)
plants with heads composed of many florets: aster, daisy, dandelion, goldenrod, marigold, lettuces, ragweed, sunflower, thistle, zinnia	coarse herbs having small heads of greenish flowers followed by burrs with hooked bristles