Asterion was one of the three river-gods (the other two being Inachus and Cephisus) who awarded the territory of Argolis to Hera over Poseidon. Poseidon, in anger, made the waters of all three rivers disappear so that they don't flow unless it rains, and are dry in summer.
Asterion in the herbal of Dioscurides, is Silene linifolia. Of this herb, found near the Heraion of the Argolid, Pausanias noted "On its banks grows a plant, which also is called asterion. They offer the plant itself to Hera, and from its leaves weave her garlands."