Ficaria from Latin for “fig” from the appearance of the root tubers.
Verna from Latin vernus meaning “spring-like”.
Part of large genus “Ranunculus”, which has about 600 species including “Buttercup” and “Marsh Marigold”.

I suspect that there was confusion naming this plant. It flowers before “Swallows” arrive. A totally unrelated plant called “Greater Celandine” has very similar flowers which come out a couple of months later….when swallows are arriving!
Lesser Celandine has been called “Spring messenger”. It is a plant native to the UK. In 2007, it was classed as “the most thriving wild plant in Britain”. It’s spread had increased 14% in 5 years! In the USA, it is classed as “invasive” by 17 states. It grows particularly well in damp, shady places, and can out compete other woodland flowers.
The root system produces finger shaped tubers, which may break off and grow another plant. These tubers have a similar appearance to haemorrhoids, and Lesser Celandine was once known as “Pilewort”!
In medieval times, some people believed that God indicated how a plant should be used, by creating a specific sign. This broad concept was called the “Doctrine of Signatures”. They thought that root tubers that looked like haemorrhoids was a signature for herbalists to use the roots, boiled, for the treatment of piles.
The ancient Greek physician, Galen, stated that sniffing a mixture of the juices of the roots mixed with honey, was good for clearing the head of “foul and filthy humours”.
In Germany it is known as “Scurvygrass”. The leaves are rich in Vitamin C, and at the end of a long winter, it must have been great to be able to eat some fresh greens. Unsurprisingly, many UK foragers eat the leaves in salads. They are said to have a “pleasant taste, if a little bitter”….hardly a ringing endorsement.
The tubers can be boiled and eaten as potatoes or sweet chestnut….they are pretty small though!
The waxy bright yellow flowers will shut when the sun goes down, opening when the temperatures rise in the morning. This is called “nyctinasty” and is thought to protect the pollen.
When leaves of the Lesser Celandine” are crushed or bruised, they release ranunculin, which breaks down further to the rather toxic protoanemonin. This compound causes mouth blisters and general gut irritation.
In some parts of the world, they use the plants toxic properties to treat nonhealing wounds. It is also used for respiratory ailments, head and muscular aches, and modern science is investigating some of protoanemonin’s useful physiological properties.
Lesser Celandine was William Wordsworth’s favourite flower, and he wanted it depicted on his tomb.
He is buried at Grasmere, in the Lake District, but the local stonemason did not know his wild flowers. He carved an image of the unrelated “Greater Celandine” instead!
This beautiful, bright ray of Spring is a hugely useful early source of nectar for many insects.
I shall not eat it, consider it’s use for haemorrhoids, of sniff it to clear my head (although my foul humour probably needs an improvement!). I shall join with the Victorians who used it to symbolise “joys of things to come”
There is a Flower, the Lesser Celandine,
That shrinks, like many more, from cold and rain;
And, the first moment that the sun may shine,
Bright as the sun himself, ’tis out again
William Wordsworth (1770-1850)