Where does “αμάραντος” come from?

αμάραντος (Greek) comes from Ancient Greek ἀμάραντος, from Ancient Greek ἀ-, from Proto-Hellenic hə-, from Proto-Indo-European sm̥-, from Proto-Indo-European sem- — together, one.

αμάραντος (Greek): undying, unwilting, unfading, eternal; amaranth;...