In Greek mythology, Salmacis (Ancient Greek Σαλμακίς) was a naiad of a spring near Halicarnassus in Caria. Unlike her sisters she rejected Artemis' hunt for vanity and leisure; Ovid's Metamorphoses makes her the nymph who forcibly embraces Hermaphroditus until the gods fuse their bodies. The same spring was said to soften men who bathed there.
Adapted from Wikipedia, "Salmacis" · CC BY-SA 4.0
I.Ovid's metamorphosis
Ovid (Metamorphoses 4) presents Salmacis as the only naiad unfit for Diana's band: she bathes, tends her hair, and refuses the chase. When Hermaphroditus, child of Hermes and Aphrodite, swims in her pool, she confesses her love; he rejects her and she withdraws, then returns and seizes him as he emerges.
She prays that they never be parted; the gods answer by merging their bodies into one androgynous form. Hermaphroditus then curses the fountain so that every man who bathes there will likewise be softened — a prayer his parents grant.
II.Other versions
A Halicarnassus inscription has Aphrodite name Salmacis as the nymph who nursed infant Hermaphroditus — a caregiver rather than Ovid's aggressor. Lucian implies Hermaphroditus was born androgynous because of Hermes, not transformed later against his will.
The atlas id salmacis-nymph is this Carian naiad. Homonyms of Hermaphroditus' parents and of other pool-nymphs are separate nodes.
III.Art and reception
A Pompeian fresco in the House of Venus in the Shell shows Eros between Hermaphroditus and Salmacis before their union. Later sculpture and painting — Bosio's Louvre nymph, Brock's Bather Surprised, Navez's Nymph Salmacis and Hermaphroditus — and poems by Beaumont and Swinburne keep the pool episode in European art.