I know Persephone and Demeter shared a lot of sacred plants and animals, but is the something that was only Persephone's symbol? Or maybe something that she shared with Hades? Now that I think about it, besides black livestock I don't think I've read ab
The asphodel was sacred to both Hades and Persephone. In the Suda, a Byzantine encyclopedia from the 10th century CE, it says that the Rhodians adorned the statues of Kore and Artemis (I’m guessing it’s Hekate, since she was sometimes seen as an aspect of Artemis) with wreaths of asphodel.
Then there’s the pomegranate, of course. It seems to have symbolized blood and death, but also fertility and marriage (and as such it was associated with Hera and Aphrodite as well).
On Locrian pinakes Hades and Persephone are often shown together with roosters, but I think it is unclear what the rooster is supposed to represent in this context. It could be a fertility/sexuality symbol and refer to Persephone as the archetypal bride. Or it could represent the soul and the afterlife, referring to Persephone’s role as queen of the dead. Whatever the case, the rooster is associated with other deities as well, not just with Persephone.
As for Hades, mint and white poplar are sometimes associated with him. According to Pausanias, the white poplar was said to first have grown on the banks of the Acheron, a river in Thesprotia where it also was said that the Nekromanteion (oracle of the dead) was located. There is also a late account saying that the white poplar was once Hades’ lover Leuke (is this story mentioned by anyone else than Servius?). Likewise, mint is Hades’ metamorphosed lover Minthe in later sources, but mint (or pennyroyal) was also used to make kykeon, the drink of the Eleusinian Mysteries that were celebrated in the honor of Demeter and Persephone.
The cypress sometimes also had funerary associations, but I think it was a symbol of mourning rather than a symbol of Hades (though Hades was of course, in his capacity as lord of the dead, associated with mourning). In Athens it was custom to hang a cypress branch on the door when you had a dead person in the house.
