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.
Spotting Poison Ivy and Oak When Out and About. 1  1. Inspect vines before touching, brushing against them or walking through them. When growing as a vine, poison ivy can snake its way along trees. 2  2. Remain vigilant even during the winter months. Poison oak drops its leaves in winter, leaving a bare stem of a vine hanging down.