Pausanias Description of Greece 2.31.10

[10]
  Here there is also a Hermes called Polygius. Against this image, they say, Heracles leaned his club. Now this club, which was of wild olive, taking root in the earth (if anyone cares to believe the story), grew up again and is still alive; Heracles, they say, discovering the wild olive by the Saronic Sea, cut a club from it. There is also a sanctuary of Zeus surnamed Saviour, which, they say, was made by Aetius, the son of Anthas, when he was king. To a water they give the name River of Gold. They say that when the land was afflicted with a drought for nine years, during which no rain fell, all the other waters dried up, but this River of Gold even then continued to flow as before.

[10] Here there is also a Hermes called Polygius. Against this statue [ agalma], they say, Hēraklēs leaned his club. Now this club, which was of wild olive, taking root in the earth (if anyone cares to believe the story), grew up again and is still alive; Hēraklēs, they say, discovering the wild olive by the Saronic Sea, cut a club from it. There is also a sanctuary of Zeus surnamed Savior, which, they say, was made by Aitios, the son of Anthas, when he was king. To a water they give the name River of Gold. They say that when the land was afflicted with a drought for nine years, during which no rain fell, all the other waters dried up, but this River of Gold even then continued to flow as before.