Heucheras are more or less evergreen, clump-forming herbaceous perennials. Heuchera micrantha 'Plum Pudding' is a particular favourite of mine and my clients. It forms a compact clump of lobed, deep beetroot-purple dusted with silvery-grey leaves and slender stems to 60cm bearing insignificant white flowers. It requires a position in full sun or partial shade in moist but well-drained soil where it will make a height & spread of 0.1-0.5cm in two to five years.