Pimpernel

Yellow Pimpernel (Lysimachia nemorum)
You are more likely to see this low creeping plant whilst on a Woodland Ways course in a damp, deciduous or mixed forest, whilst its better known cousin Scarlet Pimpernel, prefers drier or better-drained soils. Both plants belong to the family Primulaceae (Primrose), but that is really all they have in common.

The challenge of using common names is highlighted by the Yellow Pimpernel, as it is a common name for several plants. In the UK, it refers to  Lysimachia nemorum, whereas in North America you would be talking about Taenidia integerrima. 

Lysimachia nemorum, is an evergreen creeping perennial herbaceous, flowering plant growing up to about 40 cm. 

The bright, dark-green leaves are opposite, oval and pointed, without serrations or hairs, growing up to 4cm.

The yellow flowers appear between May and then end of August and are about 8mm across, they are on long stalks in the axil of each leaf. They have five very narrow sepals, five pointed petals and five stamens. N.B. the pointed shape of the petals help us distinguish it from its close relative Lysimachia nummularia, or Creeping Jenny, whose yellow petals are more rounded and closer together.

The stamens have yellow filaments and anthers. The ovary is superior, forming a capsule.

The sepals are pale green, lanceolate and shorter than the petals.

Lysimachia nemorum is native to Great Britain and Ireland (and the east of mainland Europe from the Pyrenees in the south to eastern Norway in the north). It is a shade tolerant woodland plant, preferring damp habitat, so very much at home in our Derbyshire woodlands. The second part of it’s scientific name, nemorum, comes from the Latin word nemorus and means “of the woods.” It will also appear in grasslands and hedges. Where deciduous woodland has been replaced by conifers, there will be a decline in Yellow Pimpernel.

Scarlet Pimpernel (Anagallis arvensis)
A low-growing annual plant with brightly coloured flowers, most often scarlet but also bright blue and sometimes pink. The native range of the species is Europe and Western Asia and North Africa.

Traditionally included in the family Primulaceae, the genus Anagallis was placed in the family Myrsinaceae until that family in turn was included in Primulaceae in the APG III system. The genus Anagallis is included in Lysimachia by some authors.

This common European plant is generally considered a weed and is an indicator of light soils, though it grows opportunistically in clayey soils as well.

The leaves are bright green, soft, ovate, sessile (attached directly by its base without a stalk or peduncle) and grow in opposite pairs along weak sprawling stems which have a square cross-section, growing to about 5–30 centimetres long.

The orange, red or blue, radially symmetricflowers, about 10–15 millimetres in diameter, are produced singly in the leaf axils from June to September. The five petals have edges that are slightly round-toothed or scalloped and have small glandular hairs.

The stamens have lollipop hairs and therefore attract a variety of pollinators, especially flies, but the flowers are also capable of auto-pollination. 

The dehiscent (splitting, at maturity, along a built-in line of weakness) capsule fruits ripen from August to October in the northern hemisphere. The weight of the fruiting body bends the stem, and the seeds are transported by the wind or rain. Blue-flowered plants (A. arvensis Forma azurea) are common in some areas, such as the Mediterranean region, and should not be confused with the related blue pimpernel, Anagallis foemina.

Anagallis arvensis is generally unwelcome as an invasive species; it is toxic and undesirable in pastures. It can be found in arable fields, on roadside verges and waste ground, and on coastal cliffs. The plant is acrid and bitter, and animals avoid eating it, when ingested can cause gastroenteritis and in sufficiently high doses be fatal.

In folk medicine, in its countries of origin where it has long been familiar, the plant material has been applied externally to slow-healing ulcers and wounds. 

Scarlet Pimpernel is insecticidal, or at least is repellent to some insects, possibly by virtue of its pungent essential oil which has a characteristic smell.

The plant contains tanning agents.

It is sometimes also known ‘Old man’s weathervane’ or ‘Shepherd’s weather-glass’ as the flowers close when atmospheric pressure falls and bad weather approaches.