Centranthus

Annual or perennial herbs, sometimes subshrubs. Leaves simple, entire, dentate or pinnatisect, petiolate, becoming sessile and stem-clasping below inflorescence. Inflorescences rounded to elongate thyrses loosely branching into several dichasia. Flowers small, sessile, red or white; bracts scale-like; sepals 10–23, connate in a short tube, plumose, inrolled at anthesis, enlarging and becoming visible only in fruit; corolla zygomorphic, 5-lobed, with a slender tube 3–5 times longer than lobes, upper lobe usually longer and spurred; stamen 1, filament inserted in throat of corolla-tube, style slender, stigma entire or 3-branched. Cypsela dry, surmounted by persistent calyx-lobes, scarcely ridged where 2 cells aborted.