shirt button: a button on a shirt
button: a round fastener sewn to shirts and coats etc to fit through buttonholes
bryophyta: a division of nonflowering plants characterized by rhizoids rather than true roots and having little or no organized vascular tissue and showing alternation of generations between gamete-bearing forms and spore-bearing forms; comprises true mosses (Bryopsida) and liverworts (Hepaticopsida) and hornworts (Anthoceropsida)