trailing four o'clock vs genus Allionia

trailing four o'clock and genus Allionia both are nouns.

Word	Noun	Adjective	Verb	Adverb
trailing four o'clock	Yes	No	No	No
genus Allionia	Yes	No	No	No

trailing four o'clock (noun)	genus Allionia (noun)
trailing plant having crowded clusters of 3 brilliant deep pink flowers resembling a single flower blooming near the ground; found in dry gravelly or sandy soil; southwestern United States and Mexico	small genus of chiefly American herbs