About Erica mackayana Bab.
Erica mackayana Bab. is a subshrub that typically reaches 20 to 30 centimetres (7.9 to 11.8 inches) in height, and rarely grows as tall as 90 centimetres (35 inches). It produces numerous small branchlets, which are densely covered in small leaves. The leaves are elliptical to oblong-lanceolate in shape, and arranged in whorls of four. Flower color ranges from bright reddish purple to rose pink, and flowers are typically paler on the more shaded sides of the plant. Flowers are borne in umbrella-shaped clusters called umbels at the tips of branchlets, with 10 to 12 flowers per umbel. Its sepals are hairless except for cilia along their edges, and its anthers bear long, tapering (subulate) appendages. This species is native to Spain, and is widely thought to have been introduced to Ireland, despite often being listed as native to the island; it holds a Hiberno-Lusitanian distribution. Micheline Sheehy Skeffington hypothesizes the species was brought to Ireland during the medieval period, possibly via trade, smuggling, or carried by pilgrims returning from Santiago de Compostela. A 2023 study found that Irish populations of E. mackayana are genetically connected to multiple distinct Spanish populations, indicating more recent introductions, such as via 19th and 20th century trade routes. In Spain, E. mackayana grows in Atlantic wet heathlands, a habitat protected under the European Union's Habitats Directive. Its populations in this habitat are maintained by grazing, particularly from wild ponies. This habitat occurs in northern Spain, between Santander and A Coruña. In a 1955 article about E. mackayana, D. A. Webb recorded populations ranging from Mondoñedo in the west to Cabezón de la Sal in the east. The species does not generally occur south of the Cantabrian Mountains. Its altitudinal range in Spain is 0 to 1,680 metres (0 to 5,512 feet) above sea level (it has been recorded at sea level in Colunga), and it is much rarer at elevations above 1,000 metres (3,300 feet). In Ireland, E. mackayana grows in wet heathland and peat bogs in the counties of Kerry, Mayo, Galway, and Donegal. Documented Irish locations include Lough Nacung Upper, Bellacorick, Nephin Beg, Roundstone Bog, Carna, and Caunoge in Kerry. The Lough Nacung Upper population was discovered in 1954, and spread across almost the entire northeast edge of the lake as well as part of its southwest edge. The species was not found at the nearby Dunlewey Lough or Lough Nacung Lower. The habitat at this site was described as a narrow strip of bog less than 40 metres (130 feet) wide. In Ireland, the species grows between 20 and 65 metres (66 and 213 feet) above sea level. In Ireland, E. mackayana reproduces only vegetatively, but it commonly hybridizes with Erica tetralix to produce the hybrid Erica × stuartii. In Spain, E. mackayana hybridizes only very infrequently, so E. × stuartii is extremely rare there. Like other heath species, Erica mackayana is grown in cultivation. It was first brought into cultivation in 1835, and became popular with gardeners because its cuttings usually root and grow successfully.
