Common Name:

General Information

Caltha natans is a herbaceous perennial plant producing branched stems 20 - 50cm long. The plant is often submerged with the leaves floating on the surface of the water, when in muddy ground the stems creep over the ground, rooting at the nodes[, ].
The plant is harvested from the wild in times of shortage and used as a food. It is sometimes grown as an ornamental in the garden.
The species is widespread and while it is possibly declining in parts of its range, it is not thought that any global population decline is likely to meet (or be close to meeting) the threshold for Vulnerable. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

The whole plant, but especially the older portions, contains the toxic glycoside protoanemonin - this is destroyed by heat[]. Symptoms of poisoning include a burning sensation in the throat, vomiting, bloody diarrhoea, dizziness, fainting, and, in large doses, convulsions. However, the toxicity is of a fairly low order and the plant would usually need to be eaten in quantity in order to cause major symptoms[]
The sap can irritate sensitive skin[].

Botanical References

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Range

Northern N. America - Alaska to Northwest Territories, south to Wisconsin; E. Asia - eastern Siberia, Far East, Mongolia, northern China

Habitat

Floating or on moist mud, ponds, lakes, slow-moving rivers and streams; at elevations from 25 - 1,500 metres[]. Wet meadows, marshes and in water in China[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.30 m
Pollinators	Bees, Beetles, Flies
Cultivation Status	Ornamental, Wild

Cultivation Details

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[].

Edible Uses

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.

Medicinal

Used in the treatment of sore throats[].

Other Uses

None known

Propagation

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.