A plant of boggy soils and shallow pond margins, it requires a deep rich slightly acidic soil. It grows well in heavy clay soils. Plants are hardy to about -20°c. A greedy plant, inhibiting the growth of nearby plants, especially legumes. There is some disagreement over the correct name for this species, with some authorities calling it C. howellii.

Root - cooked. A survival food, used when all else fails. Some caution is advised, see the notes above on toxicity. Flower buds - cooked. Added to stews etc or pickled as capers. Some caution is advised, see the notes above on toxicity. Young leaves - cooked. Best before the plant flowers. Some caution is advised, see the notes above on toxicity.

Seed - best sown as soon as it is ripe in a cold frame in late summer. Stand the pots in 2 - 3cm of water to keep the soil wet. The seed usually germinates in 1 - 3 months at 15°c. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a tray of water in a cold frame until they are at least 15cm tall. Plant them out into their permanent positions in the summer. Division in early spring or autumn. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the summer or following spring.

Wet alpine and sub-alpine places. Bogs and wet ground by streams, 1500 - 3000 metres.