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.
Description: Prickly Pear is a native perennial in the Cactus family (Cactaceae) that spreads along the ground and grows to 0.5 m tall. The pads (stem segments) are glossy green and have areolas (areas where spines are attached) with minute, barbed, deciduous spines called glochids.ids to Identification: Prickly Pear can be observed any time of year, though it is easiest to find in summer when the showy yellow flowers are present. The pads are oblong-obovate, about 5 to 17.5 cm Ã 4 to 12 cm in size, and dark to shiny green with areolas arranged in a diagonal pattern.