— peristomal, peristomatic /per'euh steuh mat"ik/ , peristomial , adj.
/per"euh stohm'/ , n.
1. Bot. the one or two circles of small, pointed, toothlike appendages around the orifice of a capsule or urn of mosses, appearing when the lid is removed.
2. Zool. any of various structures or sets of parts that surround or form the walls of a mouth or mouthlike opening.
[ 1790-1800; peristoma. See PERI-, -STOME ]