Palmae vs Palmaceae

Palmae and Palmaceae both are nouns.

Word	Noun	Adjective	Verb	Adverb
Palmae	Yes	No	No	No
Palmaceae	Yes	No	No	No

As nouns, Palmae and Palmaceae are synonyms defined as:

Palmae and Palmaceae: chiefly tropical trees and shrubs and vines usually having a tall columnar trunk bearing a crown of very large leaves; coextensive with the order Palmales

Other synonyms of Palmae include Arecaceae, family Arecaceae, family Palmaceae, family Palmae, palm family.

Palmae (noun)	Palmaceae (noun)
chiefly tropical trees and shrubs and vines usually having a tall columnar trunk bearing a crown of very large leaves; coextensive with the order Palmales	chiefly tropical trees and shrubs and vines usually having a tall columnar trunk bearing a crown of very large leaves; coextensive with the order Palmales