De fluviīs (Latin for "concerning rivers"), also called Dē fluviōrum et montium nōminibus et dē iīs quae in illīs inveniuntur ("concerning the names of rivers and mountains and those things which are found in them") or the Greek Περὶ ποταμῶν καὶ ὀρῶν ἐπωνυμίας, is a Greek text by Pseudo-Plutarch written during the 2nd century CE.
[1] It discusses twenty-five rivers in Greece, Asia Minor, India, Gaul, Egypt, Scythia, and Armenia.
The chapters typically start with a myth about the river, include information about local flora and stones, and end with details about a nearby mountain.
Most of the plants and stones described have mystical qualities to them, from warding off spirits and gods, to causing and healing madness, to exposing liars and thieves.
Heidelbergensis 398, which includes a marginal note stating, "This is pseudepigraphic, for the intellectual level and diction are far from the genius of Plutarch.