The Cowslip, Primula veris (a perennial in the family Primulaceae), is one of the delights of May. It flowers a few weeks later than its close relative, the Primrose, Primula vulgaris, which I wrote about in March 2012. Here in Norfolk, it is especially common on verges in parts of South Norfolk and you can see masses on the banks of the A11 Wymondham bypass (where it was deliberately planted). Nationally, the plant declined in the mid twentieth century as grasslands were ploughed up or “improved” with artificial fertilisers, but it is still quite widespread. The current and past distribution in the British Isles is shown in the Online Atlas of the British and Irish Flora. The online article “Biological Flora of the British Isles: Primula veris L.” by Brys and Jacquemyn has a European distribution map and describes the Cowslip’s ecology and biology in considerable detail. Cowslips are also found in western Asia.
In mid May we stayed on the outskirts of Selborne in Hampshire, just a short walk from Noar Hill, a beautiful area of chalk grassland and scrub famous for its flowers and butterflies. Cowslips thrive here and are the food plant of caterpillars of the scarce Duke of Burgundy butterfly. The butterfly is on the wing from mid April until late May and Noar Hill is one of its strongholds. The female butterfly is very particular when choosing where to lay her eggs, avoiding plants which are too small or too leggy. Only the lushest, partially shaded plants are chosen, on north facing slopes of chalk downland. In woodlands Primrose is used as a food plant instead. If you want to read more, I recommend “The Butterflies of Britain & Ireland” by Jeremy Thomas and Richard Lewington (British Wildlife Publishing, 2014) and “In Pursuit of Butterflies” by Matthew Oates (Bloomsbury, 2016). Alan Thornbury’s Hampshire Butterflies website is a valuable guide to Hampshire’s butterflies and their best sites, including Noar Hill. We were fortunate to see several Dukes within an hour of arriving in Selborne.
Cowslip flowers are a deeper shade of yellow than primroses and have an orange base. They are arranged in an umbel, which often droops to one side, and arise on one or more stems from a rosette of wrinkled, toothed leaves which look very similar to Primrose leaves. There are some good photos on the First Nature and NatureGate websites, but you’ll need to sniff a Cowslip flower to capture its lovely scent.
Cowslips often hybridise with Primroses to form the False Oxlip, which has pale yellow flowers (like a Primrose), arranged in an umbel at the top of a stem (like a Cowslip). They bear a passing resemblance to the much rarer Oxlip, Primula elatior, which is a very localised plant of ancient woodlands.
When Cowslips were more common they were picked and used in ceremonies, such as Cowslip Sunday at Lambley in Nottinghamshire but in “Flora Britannica” Richard Mabey reported that the plant became so scarce in the area that garden grown flowers had to be used.
The name “Cowslip” may derive from the old English for cow dung or from slippery ground churned up by cattle: the disturbance of the ground by pasture will certainly help the plant to spread by seed. Other names include Paigles, Peggles, Hey-flower, Tisty-tosties and Key Flower, Key of Heaven, Lady’s Keys, Firy Cups, Petty Mulleins, Crewel and Buckles.
Cowslip leaves are edible though “not that tasty”, as are the flowers. The Plants for a Future website also lists a range of medicinal properties for the plant.
Cowslips make a lovely garden flower, in a border or naturalised in a meadow or lawn. Here, they will self seed but are very unlikely to become a nuisance. They like sun or partial shade – in deeper shade they will grow without flowering. They can be raised from seed, but I usually buy in plants and I let them do their own self seeding.