According to the Stoic philosopher Cornutus (1st century AD), Pluto wore a wreath of "phasganion", more often called "xiphion", traditionally identified as a type of gladiolus. Dioscorides recorded medical uses for the plant. For extracting stings and thorns, "xiphion" was mixed with wine and frankincense to make a cataplasm. The plant was also used as an aphrodisiac and contraceptive. It grew in humid places. In an obscure passage, Cornutus seems to connect Pluto's wearing of "phasganion" to an etymology for Avernus, which he derives from the word for "air," perhaps through some association with the color "glaukos", "bluish grey," "greenish" or "sea-colored," which might describe the plant's leaves. Because the color could describe the sky, Cornutus regularly gives it divine connotations. Pluto's twin sister was named Glauca.