Evening-primrose can be spotted into the autumn in milder weather.

Photo: Acabashi, CC BY-SA 4.0, via Wikimedia Commons

Scientific name: Oenothera biennis

Other common names: Dusk Beacon, Suncup, Sundrop

What to look for:

  • Family: Willowherb (Onagraceae).
  • Flowers: Yellow, poppy-like.
  • Leaves and stem: Tall stem, leaves in basal rosette and in spiral up stem.
  • Length: Depending on species, can be up to 1 m.
  • Where: Wasteland, verges, old quarries, sandy soils, dunes.
  • When: Flowers usually between June and September but can be seen later in the year when the weather is mild.
  • Habit: Upright.

Spot an old quarry or area of waste ground and there is a good chance of spotting Evening-primrose. This tall and distinctive plant is a pioneering and early coloniser of land we humans have abandoned. This is because it germinates readily in recently disturbed ground.

There are a handful of species found here – including Large-flowered, Common, Small-flowered and Fragrant Evening-primrose – but they hybridise with each other freely, making them difficult to separate, and pure species may well be uncommon. The plant pictured here is probably a Large-flowered Evening-primrose (Oenothera glazioviana) – because the style (the cross-shaped structure in the flower centre – see photo) is longer than the filaments – or it may be the hybrid Intermediate Evening-primrose (Oe. biennis x glazioviana ). It would take an experienced botanist to be sure!

Despite being a familiar wayside plant, Evening-primrose isn’t native to Britain. It was introduced in the seventeenth century from North America (apart from the Fragrant species, which was introduced from Chile) and is now naturalised here and across Europe.

Evening-primrose flowers are well-known for opening as dusk falls, or when storm clouds threaten overhead, mimicking the light levels of the end of the day. They are pollinated therefore by insects that are out and about at this time of the day, and are a great favourite therefore of moths.

Did you know…?

…2014 was the four-hundredth anniversary of Evening-primrose in Europe: it reached Padua in 1614.

…Evening-primrose is now a popular herbal remedy, but the seeds and whole plant were originally used by Native Americans as, respectively, a food and to make poultices to treat bruising.

More information and references:

Mabey, R., 1997. Flora Britannica. Chatto & Windus, London
Rose, F. and O’Reilly, C., 2006. The Wild Flower Key, 2nd edition. Frederick Warne, London
Rostański, K., 1982. The species of Oenothera L. in Britain. Watsonia 14: 1–34
Stace, C., 2010. New Flora of the British Isles, 3rd edition. Cambridge University Press, Cambridge

Published: October 2014
Author: Amanda Scott
Photos: Acabashi, CC BY-SA 4.0, via Wikimedia Commons