Short answers, pulled from the story.
Aglaophotis is a herb mentioned in works on occultism and in ancient Greek medical writing. The physician Dioscorides placed it within the peony family, Paeoniaceae, making his text among the earliest known references to the name.
Some researchers have speculated that Paeonia officinalis, the European peony, is the source of aglaophotis. The evidence is too limited to confirm this theory.
According to Dioscorides, peony was used for warding off demons, witchcraft, and fever. This protective role stands in direct contrast to how the plant is described in later occult texts.
The Simon Necronomicon presents aglaophotis as a means of calling upon dark forces. This is the opposite of the Dioscorides account, in which the herb wards off malevolent forces rather than summoning them.
In the Silent Hill video game series, aglaophotis appears as a fluid or tablet that can expel monstrous parasites from characters' bodies. It functions as a protective or curative item within the games' horror setting.
In Final Fantasy XI, aglaophotis is portrayed as a species of sentient, hostile plant monsters. In the video game Book of Hours, it appears as flowers the player can gather.