Floating marsh marigold
Caltha natans
Family: Ranunculaceae
What it is like
Caltha natans is a PERENNIAL growing to 0.3 m (1ft). See above for USDA hardiness. It is hardy to UK zone 2. 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
Floating or on moist mud, ponds, lakes, slow-moving rivers and streams at elevations of 25 - 1500 metres. Wet meadows, marshes and in water in China.
North-western N. America - Alaska to Canada. E. Asia - N. China, Mongolia, Siberia.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
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.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 1
Used in the treatment of sore throats.
Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.
Expectorant: Clears phlegm from the chest by inducing coughing.
Warts: Used in the treatment of warts, corns etc.
Other
Rating:
How it is grown
A plant of boggy soils and shallow pond margins, it requires a deep rich slightly acidic soil. It grows well in heavy clay soils. It has slender floating or creeping stems that root at the nodes to form new plants. 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: 0-0
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.