Oops! It's smooth breathing, after all! Pausanias says Ἀσκληπιοῦ δέ ἐστιν ἐπίκλησις
ὁ Ἀγνίτας, ὅτι ἦν ἄγνου τῷ θεῷ ξόανον· ἡ δὲ ἄγνος λύγος καὶ αὐτὴ κατὰ ταὐτά ἐστι τῇ ῥάμνῳ. In other words, Asclepius is called Agnitas because his wooden image is carved from the "chaste-tree" (ἄγνος λύγος, cf. LSJ).