Species Spotlight: Heather
By James Duncan
Learning & Engagement Officer
It may come as a surprise to learn that the term 'Heather' comprises a number of species, not just the one. The British Isles can in fact boast to have one of the richest ranges of Heather species anywhere in the world, though there are three distinct and common varieties you're most likely to see. All have a demand for acidic soils, so it's upon our heaths, moors and bogs that they'll predominantly be found, though don't be surprised to stumble upon them within peaty soils amongst dappled woodland. One of the planet's rarest habitats, lowland heath, is dominated by specialist plants like heather who thrive in the infertile soils on only a meagre supply of nutrients. It's in the south and east of England that the vast majority of this unique habitat resides. Whereas most of the British countryside begins to lose its freshness by August, it's at this time when the heathers explode into a riot of colour, huge spaces positively glowing purple and mauve. Where blooming Heather and bright yellow Gorse grow together, they provide a magnificent patchwork of dazzling colour.
The most widely distributed of the three common species, Common Heather (Calluna vulgaris) is also considered the only 'true heather' among them, alternatively known as 'Ling.' It also happens to be the sole member of its genus. Its alternative name derives from the Old English word 'lig' meaning 'fire' which only serves to emphasise its vital importance as a past source of fuel. It's propensity for burning means that heathland fires can prove devastating and quickly spread out of control. The delicate little flowers form loose spikes atop stems that bear tiny, stubby, stalkless leaves situated in pairs. Though typically a pale pink, the flowers may occasionally range from white to a deep crimson. The extreme variation and defined growth stages of Common Heather may see it reaching over a metre in height and living to more than thirty years old. Its latin naming of Calluna derives from the Greek 'to brush', indicative of its usefulness when tied together to create a stiff broom. This ultimately translated into a multitude of practical uses - from rope-making to a source of bedding material and for thatching roofs. It has also served to create a legendary beverage, Heather Ale, something the Scottish Picts were renowned for.
Bell Heather © Graeme Lyons
The two other numerous species are known technically as 'heaths', the somewhat confusingly named Bell Heather (Erica cinerea) and Cross-leaved Heath (Erica tetralix). Whereas both display a 'bell-shaped' flower, you'll find Bell Heather frequently growing with 'Ling.' Establishing the difference between the two 'Erica' species may prove remarkably useful for Bell Heather grows on drier, well-drained soils whereas Cross-leaved Heath shows a typical preference for damp places and wet hollows. Should you be following a path on wet ground, you'll be less likely to end up waist deep in a bog should you stick closer to the Bell heather - it'll grow on the driest tussocks. Bell Heather typically shows the widest variation in flower colour of the three species, though it's the Latin name of Cross-leaved Heath (tetralix) that determines the main difference between the two. It comes from the Greek for 'four' where its tiny, short-stalked leaves form a cross when seen from above. The leaves of Bell Heather are contained within a whorl of three. Both have leaves rolled at their edges, specially adapted for water conservation through reduced evaporation. They usually flower a little earlier than 'Ling', from mid-summer, though 'Ling' may continue to provide a blazing spectacle all the way through to October.
Cross-leaved Heath © Roger Wilmshurst
At first appearance you might be forgiven for thinking that heather forms an entirely impenetrable vegetative mat, often as far as the eye can see. But the truth is, the distinct stages of its evergreen growth equate to a number of simply magnificent 'micro-worlds.' Among the individual plants, there may be patches of bare land, perfect for basking reptiles, roving grasshoppers, armies of ants and solitary bees and wasps looking to excavate their nest chambers. The plants themselves provide food for beetles, bugs, flies and the larvae of a huge number of moth species, as well as butterflies such as the striking Silver-studded Blue and eye-catching Green Hairstreak. The flowers offer an abundant nectar source for bees and a whole range of other insects. As the heather grows older and denser, its shady canopy allows for the growth of a multitude of mosses, lichens and fungi whilst heathland birds like the beautiful Dartford Warbler carefully conceal their nests and spiders busily hunt and trap their insect quarry. As the weather finally grows colder, the seeds ripen and become a welcome food source for birds, whilst the growing tips prove popular with hungry deer. Heathers play a pivotal central role in sustaining a whole community of animals, each and every one of which depend on it for breeding sites, food and protective cover.