Iodine is a chemical element with symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black metallic solid at a standard conditions that sublimes readily to form a violet gas. The elemental form was discovered by the French chemist Bernard Courtois in 1811.
Definition of CHOLLA. : any of numerous shrubby opuntias chiefly of the southwestern United States and Mexico that have needlelike spines partly enclosed in a papery sheath and cylindrical joints âcalled also cholla cactus.
Cholla is a term applied to various shrubby cacti with segmented branches. The jumping cholla, Opuntia fulgida, is a very spiny cactus, usually a shrub, but sometimes more like a tree, with a number of irregular, jointed branches bearing sharp-barbed spines that are painful and difficult to remove.