In Greek mythology, Hesperia (also Hespere or Hesperie) is one of the Hesperides — the western nymphs who tend Hera's garden of golden apples. Apollodorus names her with Aegle, Erytheia, and Arethusa at Ladon's watch; Apollonius calls the same sister Hespere and has her become a poplar after the dragon's death. Distinct from place-name Hesperia (Italy/Spain) and from other mythic women sharing the evening-name.
Adapted from Wikipedia, "Hesperides" · CC BY-SA 4.0
I.Among the Hesperides
Ancient lists of the apple-guardians disagree on number and names. Apollodorus gives four: Aegle, Erytheia, Hesperia, and Arethusa. Apollonius of Rhodes prefers three — Aigle, Erytheis, and Hespere (Hespera) — while Hyginus and Servius preserve overlapping variants that still keep a Hesperia/Hesperie form.
Parentage is equally fluid: daughters of Nyx, of Atlas and Hesperis, of Phorcys and Ceto, or of Zeus and Themis. Whatever the stem, Hesperia belongs to the far-western garden watched by the hundred-headed dragon Ladon.
II.Garden and metamorphosis
The sisters tend the golden apples Gaia gave Hera at her wedding — the prize of Heracles' eleventh labour. Apollonius has the Hesperides lament Ladon's death and change into trees; Hespere becomes a poplar.
The atlas id hesperia-hesperid with kinds hesperid locks this evening nymph against geographic Hesperia and against unrelated namesakes on the Laodamia-style disambiguation pages.