Slender, forked tubers, like little white carrots, produce 20-40cm stems clothed with narrow leaves and a spike of yellowish bells. These are heavily infused with Indian red on the exterior. The inside is spotted with Morello-cherry red. The flowers give way to rich purple fruits.
This slowly makes clumps but never a weed. A lovely plant for a peat garden, or a humus-enriched soil in light shade.