Lenticel, << LEHN tuh `sehl,` >> is a round or long swelling on the bark of woody stems and roots that functions as a breathing pore. Lenticels are formed when growth areas develop beneath the cork (outer layers of the bark). Each growth area produces a mass of new growing cells. As these cells enlarge, they press against and finally break the outer layer of the bark to form a lenticel. The cells of the lenticel are separated by spaces through which air reaches the inner parts of the stem. The rounded marks on horse chestnut stems and the long marks on cherry bark are lenticels. See also Bark .
