Anagallis arvensis Seeds | Scarlet Pimpernel

Scarlet Pimpernel (Anagallis arvensis) seed — Scarlet Pimpernel (*Anagallis arvensis*): Primulaceae, native to Arable land and open ground of Europe, north Africa, and western Asia, now naturalised worldwide.

LATIN NAME: Anagallis arvensis

COMMON NAME: Scarlet Pimpernel

Plant Profile

The scarlet pimpernel earned its old name, the poor man’s weatherglass, because its flowers tell the weather. In bright sun the little five-petalled blooms open flat and scarlet, and as the sky dulls and the air thickens before rain they fold shut, a living barometer in a weedy patch. Country people read the closing petals as surely as a glass tube, and the habit is real: the flower tracks light and humidity, shutting when the light fails and the damp rises. Few wildflowers carry a folk name so exactly earned.

The plant is a low, spreading annual with small oval leaves set opposite on the stem, and the flowers stand singly on slender stalks from the leaf joints. Each bloom is five-petalled, scarlet in the common form and a clear blue in the subspecies, with a tiny red dot at the base of each petal. The closing response is quick, so a bed of pimpernel that glows red at noon can be shut tight by afternoon, and the gardener learns to glance at it the way a sailor glances at the sky.

For all its charm, the scarlet pimpernel is a weed of the field, turning up in arable land and on sunny waste ground across its range and far beyond, carried with crops to the Americas, Australia, and beyond. It is small enough to be overlooked, yet distinctive enough to be known by name in a dozen tongues, which is a rare standing for a wayside annual. In the garden it is grown on purpose as a curious wildflower and as a child’s plant, the sort of thing that teaches a young eye to watch a flower rather than merely pick it.

Children especially take to it, because no other common flower so clearly opens and shuts on a schedule they can watch. Sow a patch near the kitchen door where the weather is read at a glance, and let a corner self-sow so the weatherglass returns each year without a second sowing.

Science & Biotechnology

The red and blue forms of the flower are a study in pigment. The colour rides on anthocyanins whose exact shade shifts with the chemistry of the petal cell, so the same species can open scarlet in one place and blue a few fields away. This pH-linked shift is the botanical trick behind the two colour forms, and it is why the blue pimpernel is kept as a subspecies of its own. The pigment is the plant’s flag and its signal, and the weatherglass closes around it when the light goes.

Uses & Benefits

The plant is not just a toy. Like its relatives in the primrose family it carries triterpene saponins built on the sapogenin primulagenin, the bitter, foaming compounds that defend the leaf and that give the genus its chemical signature. These are the constituents recorded for Anagallis, and they are why the fresh plant was treated with caution in the older herbals rather than eaten as a salad green. The chemistry is mild but real, and it is the quiet reason the weatherglass was respected rather than relied on as food.

Growing from Seed

Grown on purpose, scarlet pimpernel is a free and easy annual for the sunny edge of a wildflower patch, the vegetable garden margin, or a pot on a bright step. It self-sows once happy, so a single sowing can return for years if the site is open and the soil is ordinary. Bees visit the flowers in fine weather, and the closing habit gives the patch a daily rhythm that few other flowers provide, a small theatre for the cost of a pinch of seed.

The seed is tiny and surface-sown, pressed into a finely raked bed and kept bright, because light helps it appear. Scatter it where it is to bloom, since the seedling hates being moved, and thin the tiny plants to a finger’s space once they stand. It asks for sun and ordinary ground, and it flowers quickly in the warm months, closing each dull day and opening again when the sun returns.

Do not bury the grain; a light press and a fine tilth are enough, with the bed kept from crusting while the seedling shows. Water gently so the dust does not cake, and weed early, because the plant is small and slow to shade out rivals. In cooler districts start it under cover and set the young plants out, but handle them lightly, as the sprawling stem resents a deep move and sulks for a week before it settles.

Our Take

For the same family see the primrose Primula vulgaris and the forget-me-not Myosotis alpestris, the evening primrose Oenothera biennis, and for a blue field flower the cornflower Centaurea cyanus. Scarlet pimpernel is the one to grow if you want a flower that reads the sky for you.

Herb Seeds