Definition of: penstemon

(pen·stē′mən) noun
Any member of a North American genus (Penstemon) of perennial or shrubby plants of the figwort family, with opposite leaves and variously colored flowers; the beard tongues: also spelled pensemon, pentstemon. [Var. of NL pentstemon <Gk. pente five + stēmōn thread, stamen; so called from the rudimentary fifth stamen of this genus]