genus Pteropogon vs Compositae

genus Pteropogon and Compositae both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Pteropogon	Yes	No	No	No
Compositae	Yes	No	No	No

genus Pteropogon (noun)	Compositae (noun)
genus of Australian and South African herbs including some from genus Helipterum	plants with heads composed of many florets: aster, daisy, dandelion, goldenrod, marigold, lettuces, ragweed, sunflower, thistle, zinnia