penstemon(n = noun.plant) genus penstemon - large genus of subshrubs or herbs having showy blue or purple or red or yellow or white flowers; mostly western North America;
is a kind of asterid dicot genus
is a member of family scrophulariaceae, figwort family, foxglove family, scrophulariaceae

   A large genus of subshrubs or herbs having showy blue or purple or red or yellow or white flowers; found mostly in Western North America. [WordNet 1.5]

penstemon, var. of PENTSTEMON.

cascade penstemon, cliff penstemon, davidson's penstemon, genus penstemon, golden-beard penstemon, hot-rock penstemon, jones' penstemon, lowbush penstemon, narrow-leaf penstemon, parry's penstemon, penstemon barbatus, penstemon centranthifolius, penstemon cyananthus, penstemon davidsonii, penstemon deustus, penstemon dolius, penstemon fruticosus, penstemon linarioides, penstemon newberryi, penstemon palmeri, penstemon parryi, penstemon rupicola, penstemon rydbergii, penstemon serrulatus, penstemon whippleanus, platte river penstemon, red shrubby penstemon, redwood penstemon, rock penstemon, rydberg's penstemon, scented penstemon, shrubby penstemon, whipple's penstemon