De fluviis

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. 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.

Scholars today classify it as paradoxography, or even a parody of paradoxography.

The work
Notably, Pseudo-Plutarch describes 22 of the 25 rivers as deriving their names from people who committed suicide in them. Six of the rivers were renamed twice due to suicide. Several of the mountains are also said to have gotten their names from suicides.

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.

Sources are cited throughout the book including the Treatise of Rivers by Achelaus, the Second Book of Rivers by Sostratus, the Third Book of Mountains by Dercyllus, the Third Book of Plants by Ctesiphon, and the History of Boeotia by Leo of Byzantium. A full list is given below.

Authorship
The work is considered pseudepigrapha, meaning written by someone other than the attributed author, Plutarch. It is only preserved by the 9th century codex ''Palatinus gr. Heidelbergensis 398'', which includes a marginal note stating, "This is pseudepigraphic, for the intellectual level and diction are far from the genius of Plutarch. Unless he might be some other Plutarch."

Works cited in-text
Some 49 different writers are cited with 65 works between them, including 13 on rivers, 9 on stones, 7 histories, and 12 on international relations. Five are listed as the thirteenth volume on that topic by that author. Based on the titles, there would be at least 204 works by these authors.

In comparison, Plutarch's Alexander, a much longer work, cites around 25 sources by name. The authors cited in De fluviis seem to very conveniently come in rashes of similar syllables, e.g. Ctesias (x2), Ctesiphon, Ctesippus. The text itself is highly repetitive. These facts among others cause scholars to doubt heavily that any of the works and authors cited ever existed.

However, it does provide insight into the mind of a 2nd century Greek writer, shedding some light on what they would have considered legitimate. If the intended genre was parody, then it gives insight on what a writer from the period found humorous.