Scarlet pimpernel (Anagallis arvensis) Identification

Scarlet pimpernel / Spring / Summer / Toxic

The Scarlet Pimpernel (Anagallis arvensis) is a charming wildflower often spotted brightening up fields, gardens, and roadside verges across the UK. With its vivid orange-red flowers and creeping habit, it’s hard to miss and often mistaken for an edible herb by novice foragers.

However, despite its delicate beauty, this plant is toxic and should never be consumed. Ingesting it can lead to stomach irritation and other adverse effects.

Fascinatingly, the Scarlet Pimpernel has a long history in folklore, often referred to as the “Poor Man’s Weather Glass” because its flowers close in dull or rainy weather.

In this post, we’ll explore how to identify this striking plant, where it grows, and why it’s one to admire but not to pick for your plate.


Common Names

Scarlet pimpernel, Shepherd’s sundial, Shepherd’s weather-glass


Latin Name

Anagallis arvensis


Family 

Primulaceae otherwise known as the Primrose family 


Physical Characteristics of Scarlet pimpernel

Low growing delicate annual with a creeping habit, spread is about 15-30cm 


Leaves

Smooth ovate leaf shape, in opposite pairs and attached directly to the stem with no leaf stem (sessile) bright green and hairless .

Niepokój Zbigniew, CC BY-SA 4.0

Stem

Spreads out and divides staying contained and low lying. Square cross section, but being so small you may need a magnifying glass to see this. Hairless.


Flowers

By Alvesgaspar – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3841195
Anagallis arvensis
מרגנית השדה – עין התכלת
Horashim Forest, Israel, 2014
יער חורשים, ישראל, 2014

Most commonly orange can also be red or blue flowers with five petals. Each petal has a pinky colouring towards the centre, with 5 closely positioned stamen protruding from the centre. Flowers are small 10-15 mm and appears singularly from the leaf axis.


Fruit

Dry seed capsule 


Habitat, Range and Distribution

It can be found in many places such as arable fields, woodland, on roadside verges and waste ground, and on coastal cliffs. It is an indicator species of light soils but will tolerate most.


Scarlet pimpernel Could Be Confused With

 

Chickweed -Stellaria media. When not in flower they look very similar. To tell the difference you will need to take a very close look at the stem. Chickweed has a hairy line running along the stem while Scarlet pimpernel is hairless. Once in flower the difference is very obvious as chickweed has very small white flowers. Chickweed is a lovely salad edible. 

Chickweed, shot of a plant in flower-forager James

Safety Notes

Do not ingest any part, also may cause dermatitis in sensitive individuals.


Edible Uses

Whole plant is toxic, in varying amount depending on how dry or moist the plant is.


Conservation Considerations

Once considered a weed of farmers fields, the Scarlet pimpernel is now in decline due to intensive agricultural practices.


Extra Tips and Fun Facts

The names shepherd’s sundial and shepherd’s weather-glass came about because the flowers close at 3pm and if the weather is damp or humid. Also because the flowers have a protruding center of stamen these were used like a sundial to tell the time .

The name pimpernel comes from the Old French pimprenele, the misapplied name of the burnet saxifrage, Pimpinella saxifrage

Scarlet pimpernel has been used by the ancient Greeks for medicinal use, the young leave also used to be eaten after being boiled however this plant has since been proven to have many harmful side-effects.


Resources

https://www.inaturalist.org/guide_taxa/183838 

https://www.wildlifetrusts.org/wildlife-explorer/wildflowers/scarlet-pimpernel