phellem
phel.lem \'fel-.em\ n [Gk phellos cork + E -em (as in phloem)] : a layer of usu. suberized cells produced outwardly by a phellogen
Webster's English Dictionaryphel.lem \'fel-.em\ n [Gk phellos cork + E -em (as in phloem)] : a layer of usu. suberized cells produced outwardly by a phellogen