Number sign. Not to be confused with the Chinese character äº, the sharp sign (â¯), the viewdata square (â), the numero sign (â), the equal and parallel to symbol (â) or the game Tic-tac-toe's grid. The symbol # is most commonly known as the number sign, hash, or pound sign.
The poison ivy rash is not contagious. When a person touches the poison ivy leaf, a substance on the surface of the leaf (a resin) rubs off. Over the next 48 to 72 hours the skin reacts to the resin by becoming red and developing bumps and blisters at and around the site where the resin was.
causes when people come in contact with poison ivy poison oak or poison sumac they often develop an allergic reaction that causes a rash at the site of exposure the leaves of the plant secrete a resin called urushiol u roo she ol that provokes a delayed allergic reaction one day or more after exposure to the skinoison ivy is a common weed like plant found in many parts of the country most commonly in the central and eastern u s it is an invasive bush with vines that can climb in and around neighboring plants