Marsh Marigold, Yellow marsh marigold
Caltha palustris
Family: Ranunculaceae
What it is like
Caltha palustris 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 March to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, beetles, flies. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) 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
Wet areas in marshes, fens, ditches and wet alder woods. Rare on very base poor peat.
Much of the northern Temperate zone in Europe, including Britain, N. America and Asia..
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 2
Root - must be well cooked. The raw root should not be eaten. Some caution is advised, see the notes above on toxicity. Flower buds - raw, cooked or pickled and used as a caper substitute. Eating the raw flower buds can lead to intoxication. Some caution is advised, see the notes above on toxicity. Young leaves - raw or cooked. The leaves are harvested in the spring as the plant is coming into flower and is used like spinach after cooking in two or more changes of water. Eating the raw leaves can lead to intoxication. Some caution is advised, see the notes above on toxicity. Older leaves, before the plant flowers, can be eaten if they are well cooked. Some caution is advised, see the notes above on toxicity.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 2
Every part of this plant is strongly irritant and so it should be used with caution. The whole plant is anodyne, antispasmodic, diaphoretic, diuretic, expectorant and rubefacient. It has been used to remove warts and is also used in the treatment of fits and anaemia. The root is antirheumatic, diaphoretic, emetic and expectorant. A decoction is used in the treatment of colds. A poultice of the boiled and mashed roots has been applied to sores. A tea made from the leaves is diuretic and laxative. All parts of the plant can irritate or blister the skin or mucous membranes.
Anodyne: Relieves pain, it is milder than an analgesic.
Antirheumatic: Treats rheumatism.
Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.
Diaphoretic: Induces perspiration.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Expectorant: Clears phlegm from the chest by inducing coughing.
Irritant: Causes irritation or abnormal sensitivity in living tissue.
Rubefacient: A counter-irritant and external stimulant, it produces inflammation and redness of the skin.
Warts: Used in the treatment of warts, corns etc.
Other
Rating: 3
A yellow dye is obtained from the flowers, a saffron substitute. It is used as a dye when mixed with alum, though it is not very permanent. Plants can be grown for ground cover when planted about 45cm apart each way.
Dye: Plants that provide dyes.
Attracts Wildlife: Plants noted for attracting wildlife
Ground cover: Ground Cover
How it is grown
A plant of the waterside, it prefers growing in a sunny position in wet soils or shallow water up to 15cm deep, though it will tolerate drier conditions if there is shade from the summer sun. Another report says that it grows best in partial shade. Requires a deep rich slightly alkaline soil. Grows well in heavy clay soils. Prefers a chalky soil. Tolerates a pH in the range 4.8 to 7.5. A very ornamental and polymorphic plant, there are some named varieties. Plants often self-sow when well sited. A good bee plant. A greedy plant, inhibiting the growth of nearby plants, especially legumes. This species is probably the most primitive flower in the British flora.
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: Ground Cover; 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 protoanemonin - this is destroyed by heat. The sap can irritate sensitive skin.