Raphides are needle-shaped crystals of calcium oxalate monohydrate or calcium carbonate as aragonite, found in more than 200 families of plants. Both ends are needle-like, but raphides tend to be blunt at one end and sharp at the other.

The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe. Also known as the arum family, members are often colloquially known as aroids. This family of 140 genera and about 4,075 known species is most diverse in the New World tropics, although also distributed in the Old World tropics and northern temperate regions.