Erica (plant)

European species

Most European species are dwarf shrubs, growing 20–80 cm tall. The largest are the tree heather (Erica arborea) and the broom heather (Erica scoparia), which can reach 6–10 meters.

African species

The majority of the more than 750 African heather species occur in the fynbos of the Cape region of South Africa, where they grow alongside Protea species and other shrubs. Most South African species have long, disc-shaped flowers. In the Afromontane zones of East Africa, heather species that grow to several meters tall, such as Erica arborea and Erica rossii grow.

Description

Most of the species of Erica are small shrubs from 20 - high, though some are taller; the tallest are E. arborea (tree heath) and E. scoparia (besom heath), both of which can reach up to 7 m tall. All are evergreen, with minute, needle-like leaves 2 – long. Flowers are sometimes axillary, and sometimes borne in terminal umbels or spikes, and are usually outward or downward facing. The seeds are very small, and in some species may survive in the soil for decades.

Taxonomy

Dulfer published the last revision of the genus Erica in the 1960s, treating 605 species. Many new species have subsequently been described (particularly in South Africa) and a further 83 have been included in Erica from former "minor genera", such as Phillipia Klotzsch and Blaeria L. A more recent overview of Erica species is provided in an electronic identification aid, but a modern taxonomic revision of the genus as a whole is still lacking.

Phylogeny

A number of increasingly detailed phylogenetic hypotheses for Erica have been published based on nuclear ribosomal and plastid DNA sequences. The closest relatives of Erica are Daboecia (one or two species) and Calluna (monospecific), representing the oldest surviving lineages of a, by inference, ancestrally Palearctic tribe Ericeae. The small number of European Erica species represent the oldest lineages of the genus, within which a single, order-of-magnitude more species-rich, African clade is nested. Within the African clade, Cape and Madagascan/Mascarene species respectively represent monophyletic groups.

Species

Main article: List of Erica species

Selected species include:

• Erica abietina
• Erica afra
• Erica agglutinans
• Erica arborea
• Erica australis
• Erica azorica
• Erica baccans
• Erica cabernetea
• Erica canaliculata
• Erica capensis
• Erica carnea
• Erica cerinthoides
• Erica ciliaris
• Erica cinerea
• Erica comorensis
• Erica cruenta
• Erica × darleyensis
• Erica erigena
• Erica grandiflora
• Erica haematocodon
• Erica hirtiflora
• Erica jasminiflora
• Erica lusitanica
• Erica mackayana
• Erica mammosa
• Erica manipuliflora
• Erica margaritacea
• Erica mollis
• Erica multiflora
• Erica nana
• Erica nyassana
• Erica patersonia
• Erica peltata
• Erica plukenetii
• Erica pyramidalis
• Erica recurvata
• Erica reunionensis
• Erica rossii
• Erica scoparia
• Erica spiculifolia
• Erica terminalis
• Erica tetralix
• Erica turgida
• Erica urna-viridis
• Erica vagans
• Erica ventricosa
• Erica versicolor
• Erica verticillata

|Baumheide.jpg|Erica arborea |Erica_cinerea_(Purpurlyng).jpg|Erica cinerea |Erica junonia00.jpg|Erica junonia |Erica mammosa flower.jpg|Erica mammosa |Erica ciliaris.jpg|Erica ciliaris |Uces en Ortegal.jpg|Heather fields in Ortegal (Galicia, Spain)

Etymology

The Latin word erica means "heath" or "broom". It is believed that Pliny adapted erica from Ancient Greek ἐρείκη. The expected Anglo-Latin pronunciation, , may be given in dictionaries (OED: "Erica"), but is more commonly heard.

Distribution and habitat

Around 690 of the species are endemic to South Africa, and these are often called the Cape heaths, forming the largest genus in the fynbos. The remaining species are native to other parts of Africa, Madagascar, the Mediterranean, and Europe.

Like most Ericaceae, Erica species are mainly calcifuges, being limited to acidic or very acidic soils. In fact, the term "ericaceous" is frequently applied to all calcifuges, and to the compost used in their cultivation. Soils range from dry, sandy soils to extremely wet ones such as bog. They often dominate dwarf-shrub habitats (heathland and moorland), or the ground vegetation of open acidic woodland.

Ecology

Plants of this genus are eaten mainly by the larvae of many Lepidoptera species, including Saturnia pavonia, garden tiger moth, true lover's knot, wormwood pug, the silver-studded blue, and the Coleophora case-bearers C. juncicolella and C. pyrrhulipennella.

Some species of sunbirds are known to visit and pollinate Erica. Two such species are the southern double-collared sunbird and the orange-breasted sunbird.

Cultivation

Erica species are grown as landscape or garden plants for their floral effect. They associate well with conifers and are frequently seen in planting schemes as massed ground cover beneath varieties of dwarf conifers. They are capable of producing flower colour throughout the year. They can also be grown in tubs or window boxes to provide interest through autumn and into winter.

The cultivation of larger beds of heath rather than individual plants became more popular in the 1920s, after gardeners began to try and replicate natural heathland environments in their gardens.

References

References

1. . (2017). ["''Erica'' Tourn. ex L."](http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30249382-2#synonyms). *Board of Trustees of the Royal Botanic Gardens, Kew*.
2. Stevens, P.F. (2001 onwards). "[http://www.mobot.org/MOBOT/research/APweb/genera/ericaceaegen.html Ericaceae genera]". ''Angiosperm Phylogeny Website''. Retrieved 31 May 2022.
3. Manning, John. (2007). "Field Guide to Fynbos". Struik Publishers, Cape Town.
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5. Galley, C.. (2006). "Geographical affinities of the Cape flora, South Africa". Journal of Biogeography.
6. "Plantweb picture gallery: Erica".
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8. Dulfer, H. (1964). "Revision der Südafrikanischen Arten der Gattung ''Erica'' L. 1 Teil". Annalen des Naturhistorischen Museums in Wien.
9. Dulfer, H. (1965). "Revision der Südafrikanischen Arten der Gattung ''Erica'' L. 2 Teil". Annalen des Naturhistorischen Museums in Wien.
10. Oliver, E.G.H.. (2000). "Systematics of Ericeae (Ericaceae-Ericoideae): species with indehiscent and partially dehiscent fruits". Bolus Herbarium, University of Cape Town.
11. (2012). "Genus Erica An Identification Aid Version 3.00". Contributions from the Bolus Herbarium.
12. (2005). "Phylogenetic Relationships of European and African Ericas". International Journal of Plant Sciences.
13. (2015). "Testing reticulate versus coalescent origins of ''Erica lusitanica'' using a species phylogeny of the northern heathers (Ericeae, Ericaceae)". Molecular Phylogenetics and Evolution.
14. (2011). "A densely sampled ITS phylogeny of the Cape flagship genus ''Erica'' L. suggests numerous shifts in floral macro-morphology". Molecular Phylogenetics and Evolution.
15. (2016). "The biodiversity hotspot as evolutionary hot-bed: spectacular radiation of ''Erica'' in the Cape Floristic Region". BMC Evolutionary Biology.
16. Scarborough, John. (1992). "Medical Terminologies : Classical Origins Oklahoma Series in Classical Culture". University of Oklahoma Press.
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18. (1995). "Sunset Western Garden Book". Leisure Arts.
19. Manning, John. (2012). "Plants of the Greater Cape Floristic Region: 1: the core Cape flora". South African National Biodiversity Institute, SANBI.
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21. (1999-02-01). "Population differentiation and conservation of endemic races: the butterfly, Plebejus argus". Animal Conservation.
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23. (1989). "Heathers in Colour". Blandford Press.