Where does “καλάμι” come from?

καλάμι (Greek) comes from Ancient Greek καλάμιον, from Ancient Greek κάλαμος, from Proto-Indo-European ḱolh₂-m-, from Proto-Indo-European kolH- — to raise, to lift, to build; awn.

καλάμι (Greek): reed, plant with hollow stem; shin; telescopic...