The marsh marigold (scientifically Caltha palustris) is a plant that belongs to the genus of marigolds and is related to the buttercups.
The plant is deciduous, perennial and herbaceous. Depending on the location, marsh marigold reaches a height of 15 to 60 cm. It has arching to erect, glabrous and hollow stems that have branching at the top.

The leaves are long-stalked and the ones on the upper stem have almost no stalk.
Their color is dark green, shiny and are about 15 cm in diameter. The shape of the leaves is bean to heart-shaped and they are notched at the leaf edges and not divided.
The flowering period of the marsh marigold begins in March and lasts until the month of April or June, depending on the location. Now and then there is a weaker second flowering period between July and October. Each stem usually has a few flowers, which are hermaphroditic and radially symmetrical. Their perianth usually has 5 oval and wide perigone leaves, which have a length of about 2 cm. There is no calyx. The marsh marigold has many stamens in yellow and between 5 and 15 carpels, which are narrow and free. The glands for nectar are at the bottom of these carpels.

Once the carpels are fertilized, a bellows fruit ripens in a slender shape. The ripened bellows fruits have a star-shaped arrangement. Their mature seeds are dark brown and about 2.5 mm long. They are arranged in 2 rows inside the bellows fruit.
The marsh marigold grows in continental and northern Asia, Europe and North America. On the European continent it is spread as far as Arctic Russia and Iceland.
Its habitats are banks of springs and streams, marsh meadows, floodplain forests and ditches. It tolerates changing water levels well. Common neighboring plants are cabbage thistle, meadowsweet, marsh forget-me-not, snake’s knotweed, black alder, and cuckoo’s campion.
At Bavarian Rappensee, marsh marigold grows at elevations up to 2,050 meters.

Marsh marigolds are not eaten by grazing animals.
Although the plant is poisonous, it was nevertheless used in the past as a coloring agent for cheese and as a food and stimulant. Its leaves were a traditional salad green with a pungent, spicy flavor in Spain and a means of flavoring vinegar and wine in England. Marsh marigold buds were a substitute for capers in times of crisis, but have little importance as a food substitute today.
Because marsh marigold buds contain anemonin, high consumption of these substitute capers carried the risk of skin rash, diarrhea, and nausea.
When the plant components are cooked, their toxicity decreases. For this reason, it was recommended to change the cooking water at least twice.
Today, the consumption of all components of this plant is not recommended.
The ancient Greeks and Romans did not know the plant species marsh marigold as a medicinal herb. In the 15th century, a distillate of the plant was mentioned as a remedy for eye ailments.
In folk medicine, marsh marigold was a medicinal plant only in isolated cases. The herb was used within Central Europe for menstrual cramps and skin diseases. The Russians used marsh marigold as a laxative and urinary stimulant. Its leaves were a respected wound remedy for insect bites and served as an aid for broken bones, scab wounds, and smoker’s lung.
In modern medicine, the marsh marigold is no longer used, because today the plant serves only homeopathic purposes.
Just like numerous other plants blooming in spring, the marsh marigold was a repellent for demons among some peoples. At Walpurgis it was collected and scattered in front of the entrances to the cattle stables to ward off witches. The cattle also got the plant mixed into the feed, for a beautiful yellow tone of the butter throughout the year. The Danes and Icelanders also used the marsh marigold as a protective agent at Walpurgis.