Western Marsh Marigold, Howell's marsh marigold, Sulphur marsh marigold
Caltha leptosepala

Family: Ranunculaceae

What it is like

Caltha leptosepala is a PERENNIAL growing to 0.3 m (1ft) by 0.3 m (1ft in). See above for USDA hardiness. It is hardy to UK zone 3. It is in flower from May to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, beetles, flies. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid and neutral soils. It can grow in semi-shade (light woodland) or no shade. It prefers wet soil and can grow in water.

Height (m): 0.3

Where it is found

Open, wet, subalpine and alpine marshes, wet seepages and marshy meadows at elevations of 750 - 3900 metres.

Western N. America - Alaska to Oregon.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Root - it must be well cooked. Some caution is advised, see the notes above on toxicity. Flower buds - raw, cooked or pickled and used as a caper substitute. Some caution is advised, see the notes above on toxicity. Young leaves, before the flowers emerge are eaten raw or cooked. Some caution is advised, see the notes above on toxicity. Older leaves, before the plant flowers, can be eaten if well cooked. Some caution is advised, see the notes above on toxicity.

Root: includes bulbs, corms, tubers, rhizomes etc.

Medicine

Rating: 1

The whole plant is antispasmodic and expectorant. It has been used to remove warts. A poultice of the chewed roots has been applied to inflamed wounds.

Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.

Expectorant: Clears phlegm from the chest by inducing coughing.

Poultice: A moist, usually warm or hot, mass of plant material applied to the skin in the treatment of burns etc.

Warts: Used in the treatment of warts, corns etc.

Other

Rating:

How it is grown

A plant of the waterside, it prefers growing in a sunny position in wet soils or shallow water, though it will tolerate drier conditions if there is shade from the summer sun. It requires a deep rich slightly acidic soil. Grows well in heavy clay soils. Plants are hardy to about -20c. A greedy plant, inhibiting the growth of nearby plants, especially legumes.

Propagating it: 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.

Best place to grow: Pond; Bog Garden;

Habit: Perennial

Hardiness: 3-7

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Wet, water

Things to keep in mind

The whole plant, but especially the older portions, contains the toxic glycoside protoanemanin - this is destroyed by heat. The sap can irritate sensitive skin.

Its other names

Local names

Synonyms

C. rotundifolia.