Where does “Acaena” come from?

Acaena (Translingual) comes from Ancient Greek ἄκαινα, from Ancient Greek ἀκή, from Proto-Indo-European h₂eḱ- — sharp.

Ancestry of “Acaena”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἄκαινα	spike, prick, goad; ten foot rod, used as a...
2	Ancient Greek	ἀκή	point; silence; healing
3	Proto-Indo-European	h₂eḱ-	sharp

Acaena — Etymology, Origin & Word History | Etymology Explorer