A new combination in Erica ( Ericaceae )

A new nomenclatural status and combination is proposed for Erica cinerea var. numidica. New data about the morphology, chorology and ecology of this taxon are given.

Erica cinerea s. l. is a taxon of the section Brachycallis I. Hansen and it has an Atlantic distribution in its wider sense (Dupont, 1962;Roisin, 1969).It also appears in two sites far from the main area of distribution of the species.One of them is the island of Madeira (McClintock, 2001: 249), where it was first described as a variety and later elevated to specific status under the name of Erica maderensis (Benth.)Bornm., see McClintock (1989) and Hansen & Sunding (1993).
A second nucleus can be found on the east Algerian coast, from where it was first reported by Battandier (1919) as Erica cinerea and later as a new taxon: E. cinerea var.numidica by Maire (1931).Quézel & Santa (1963) and Greuter et al. (1986) ratified the presence of this taxon in Algeria.These populations there exhibit particular morphological characters that separate them from the European and Macaronesian ones.

Morphology
It is a taxon morphologically close to Erica cinerea, isolated from the continuous area of the European populations, which exhibits a series of morphological peculiarities that are summarized in Table 1.
The morphology of the seeds provides taxonomic characters that should be used in the taxonomy of these species of the genus Erica (Table 1; Fagúndez & Izco, 2008, 2009).

General distribution
Erica numidica, described initially by Maire (1931) and mentioned repeatedly from Algeria by numerous authors (Quézel & Santa, 1963;Greuter et al., 1986;Charco, 2001), exhibits a considerable geographical isolation from the close relative E. cinerea.To date, Erica numidica is only known from the summit of the Koudiat Tella and the Jbel Koursi (200-300 m), some kilometers to the south of the first locality, both lying within the Democratic and Popular Republic of Algeria.Quézel & Santa (1963) mentioned it from the area surrounding Cap Rosa, where it is reported as being very rare.
Erica cinerea has its southern limits in Liguria (Pignatti, 1982) and Catalonia (Dupont, 1962), being absent from the Italian Peninsula, the southern half of Spain and Morocco.The large distance separating that species from Erica numidica could be a reason for the emergence of morphological differences and formation of a species.Similar vicariants, furthermore, can be found among several other taxa (Romo & Boratyński, 2007;Terrab et al., 2007Terrab et al., , 2008;;Habel et al., 2009).The period of isolation is lately estimated as from the end of Messinian Salinity Crisis, which occurred approximately 5 million years ago (Krijgsman et al., 1999).
Incomprehensibly, the website Aluka ( 2010), where specimen sheets from herbarium MPU (Montpellier) and from herbarium P (Paris) can be seen, apart from the label containing numerous transcriptional errors, assigns the plants from these herbaria to Tunisia when in fact they correspond to localities in Algeria.The error comes from the locality expressed on the label: "ad occid.urbis Tunizae", which is merely orientative.

Ecology
The ecology of Erica numidica is also singular, since it departs from the typical heath formations of Atlantic affinity and is found in plant communities of a clearly Mediterranean character.These heathers (or heaths), according to Quézel & Santa (1963), are a constituent of the cork oak forests' understorey and, judging by the data on herbarium labels, have never been found very far from the coastline, nor do they ascend much in altitude, being found always below 300 m.At present, these populations of E. numidica are protected in the National Park of El Kala (Stevenson et al., 1988).This plant is located in the regional hot-spot of Kabylies-Noumidie-Kroumirie (Médail & Diadema, 2009) and the putative refugia of Petite Kabylie (Médail & Diadema, 2009)