genus Lactuca vs Compositae

genus Lactuca and Compositae both are nouns.

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

genus Lactuca (noun)	Compositae (noun)
an herb with milky juice: lettuce; prickly lettuce	plants with heads composed of many florets: aster, daisy, dandelion, goldenrod, marigold, lettuces, ragweed, sunflower, thistle, zinnia