From the island of Shikoku in Japan comes this remarkable aroid, growing from corms in humus-rich, moist, well-drained soils beneath a canopy of dappled shade. The inflorescence is the thing: a swollen white spadix cloaked by a spathe dark as aubergine on its outer face, pale as bone within, the whole arrangement appearing in spring with an almost theatrical deliberateness. At 1.5 to 2 feet tall and wide, it earns its position at the front of the shaded border or among the ferns of a woodland path.

Patience is required. Corms planted 3 to 4 inches deep and left undisturbed are the surest route — seed-grown plants can take 3 to 5 years to produce a bloom. Once flowering begins, summer may bring a cone of red berries before the plant retreats into dormancy by midsummer, as is the way of aroids. Plant it where its absence will be covered by later-emerging foliage, and leave it alone: Arisaema sikokianum rewards those who resist the urge to move things around.