Dreamshade are a Neverland plant species. They first appear in the fifteenth episode of the second season. It grows in thorny bushfuls that ooze a liquid poison. In its natural form, the poison causes excruciating pain in the victim for a prolonged period, with a slow death. In a concentrated dose, dreamshade still affects the victim quickly, but causes the person to expire at a faster rate.
Liam purposely cuts himself with dreamshade to prove it is harmless, but when he becomes instantly ill, Hook tries to save him with Neverland's spring water. This binds Liam to stay in Neverland forever to remain alive, but after he leaves the island, he perishes to his dreamshade wound.
Hook procures dreamshade in a concentrated dose before leaving Neverland, which he later uses in an attempt to kill Mr. Gold.
The Lost Boys coat their arrows with dreamshade, with one of these piercing David during a battle.
Gothel gives a toadstool to Rapunzel as an opportunity to curse Cecelia's heart and drive her away from Marcus. Rapunzel, at first, rejects the idea of hurting an innocent person for her own gain, but as her jealousy grows after her daughter Drizella shows favoritism towards Cecelia, Rapunzel crushes the toadstool's liquid into the woman's drink.
After Gothel's daughter, Alice, is imprisoned in the Tower, Gothel poisones her father, Hook, who has been living with her daughter, in order to punish him.
Years later, Drizella coats a knife with liquid from the toadstool in an attempt to poison Henry's heart but she fails after Cinderella arrives to save him.
Ambrosia are an Underworld plant species. They appear in the twentieth episode of the fifth season. Also known as the food of the Gods, the Ambrosia is so powerful that they absorb all the magic around them. One of their magical properties is to allow their eater to escape the Underworld. They grow at a far down point of the Underworld. To access to the field, one test must be completed. Unbeknownst to everyone, Hades cut the tree of the Ambrosia, so the plant disappeared.
Boro Grove's Spore Flowers are a Wonderland plant species. They appear in the sixth episode of the spin-off series. The spore flowers grow on trunks of Boro Grove trees, and they exude a purple-pinkish cloud of fog that gives off a fragrant perfume. Those that inhale the scent are plagued with almost instant amnesia and are drawn into a lively stupor of wanting to stay in the Boro Grove. If the person stays in this state after a short period of time, he or she will begin turning into a Boro Grove tree. The spore flowers affect humans, except for those who don't have their hearts.
Known Boro Grove's Spore Flowers:
Spore Flowers appear on all Boro Grove trees, trapping people in the forest.
When Cyrus is trapped in its vines, and while wrestling to untangle himself, the grapevine broadcasts his sounds of struggle miles away in the maze. Tweedledum hears Cyrus through the grapevine and prepares to report this to the Red Queen.
Pixie Flowers are a plant species of unknown origin. They first appear in the eight episode of the third season. There are two kinds of pixie flowers. One type is the flowers which grow in the highest of branches where they're closest to the stars in Neverland, and only blooms at night under the starlight, which is how the pixie dust within them gets its magic. The other kind is the flowers which grow in a presence of a great evil. ("Think Lovely Thoughts", "Awake")
Known Pixie Flowers:
As Malcolm climbs a tree, he spots a flower on a branch and reaches into it, takes out a handful of pixie dust, and pours it over himself.
Emma and Mary Margaret finds a very large group of pixie flowers in the presence of a great evil - the Black Fairy. They are all destroyed by Gideon by the Black Fairy's orders, but he secretly leaves one flower untouched in order to help his family.