Page 3 - Gianguzzi_alii_2012

304 L. Gianguzzi et al.

Mots-clés: Analyse des populations; biogéographie; conservation de la nature; critères de l’UICN; espèces en danger de
la région méditerranéenne; Simethis mattiazzi; Xanthorrhoeaceae

Introduction
Materials and methods
Simethis mattiazzi (Vandelli) Sacc. is the only hitherto
This research is part of geobotanical surveys carried out
known entity of a phylogenetically very isolated genus
for years in the western sector of Sicily and in the small
(Chase et al. 2000; Chase, Reveal, and Fay 2009;
circum-Sicilian islands (Gianguzzi 1999; Gianguzzi and
Euro+Med Plantbase 2006–10), first attributed to the
Ottonello 2000; Gianguzzi, Scuderi, and La Mantia
family Liliaceae (Bonnet and Baratte 1896; Fournier
2003a, 2003b; Romano, Gianguzzi, and Tobia 2003;
1961; Haslam, Sell, and Wolseley 1977; Webb 1980;
Romano, Tobia, and Gianguzzi 2006; Gianguzzi and La
Pignatti 1982; Blamey and Grey-Wilson 1991), then to
Mantia 2008). After the first discovery of the species on
Asphodelaceae (Chase et al. 2000; Valdes et al.
the Marettimo Island in 2003 (Gianguzzi, Scuderi, and
2002; Chase, Reveal, and Fay 2009), and finally – on
Pasta 2006), the investigations were extended and a
the basis of more recent systematic revisions – to
second population was found on Mount S. Giuliano
Xanthorrhoeaceae Dumort. (1829) nom. cons.,
subfamily Hemerocallidoideae (APG II 2003; APG III (western Sicily) in the spring of 2011. In both sites
2009). The distribution of this species spreads through further field checks were carried out to define the extent
the western part of Europe, with a greater gravitation of the populations and to ascertain the presence of any
in the Atlantic belt (Webb in Tutin et al. 1980) other nuclei.
extending to the north-western coasts of Morocco, with The adopted nomenclature for the species mainly
some disjointed stations located in the territories of the follows Conti et al. (2005), Giardina, Raimondo, and
Italo-Tyrrhenian Province (Pignatti 1982; Conti et al. Spadaro (2007) and Raimondo and Spadaro (2009) for
2005). references related to Italy, Flora Iberica (Castroviejo et al.
Two stations of S. mattiazzi were recently discovered 1986–2003) and Flora Europaea (Tutin et al. 1964–80)
in the regional territory of Sicily, at the south-eastern for the remaining taxa. The exiccata collected during the
limit of the range. The first of the two populations is field researches are kept at the Department of
Environmental Biology and Biodiversity of the University
located on the Marettimo Island (Aegadian Archipelago,
of Palermo (collections of one the authors); another
Channel of Sicily), where it was discovered by Prof.
sample is kept at the Herbarium of Catania (CAT), Sicily.
Brullo in 2003 (Gianguzzi, Scuderi, and Pasta 2006).
The second population was recently found in Sicily,
Taxonomical and morphological analyses
along the northern slope of Mount S. Giuliano (Erice,
Trapani Prov.). These populations are more than 300 km The taxonomical analysis was performed based on a
away from the closest Tyrrhenian sites previously known detailed bibliographic survey. The morphological
for southern Sardinia (to the north-west) and the Pontine characterization refers mainly to direct observations on the
Islands (to the north-east), and about 150 km from the two investigated populations; an original line iconography,
northern African stations of Tunisia (to the south-west). representative of the observed characteristics, was also
These finds lead to the addition of a species – as well as produced (Figure 1). Field surveys with monitoring during
a genus and a family – to the strictly insular flora of the different seasonal phases were performed to record
Sicily. However, the evolutionary significance and the observations on the biology and phenology; the
conservation status of such small isolated populations karyological structure was investigated through a
need to be evaluated to define appropriate protection bibliographic survey.
measures (Sciandrello and Tomaselli 2011; García
González et al. 2011). Chorological analysis and phytogeographical
Besides focusing on the phytogeographical interest of importance of the new findings
the new discoveries, the present work tries to give The general distribution map of S. mattiazzi (Figure 2)
answers to the following questions. (1) What are the was drawn on the basis of the data reported by Dupont
abiotic (substrate, bioclimate, exposure, etc.) and biotic (1962), Webb (in Tutin et al. 1980), Bolòs and Vigo
(synecology, co-living with endemic or rare species, etc.) (1984–2001), Bolòs et al. (2005) and Morales Del Molino
factors that characterize the habitat? (2) Are the new and Mateo (2010); the localization of the two new
populations of S. mattiazzi relictual or do they belong Sicilian stations and the other Italian stations (Béguinot
to a relictual flora? (3) What is the numerical importance 1905; Fiori 1923–29; Ricci 1972; Anzalone and Caputo
of the populations (especially in terms of mature 1974–75; Pignatti, Lucchese, and Lattanzi 1985; Baldini
individuals)? How many mature individuals are there? 1995; Selvi and Viciani 1999) were then integrated.
Do these stations, located at the extreme south-eastern The phytogeographical significance of the new
limit of the range, suffer from isolation and are they at discoveries was evaluated by an analysis of the floristic
risk? studies relating to the species and of the flora present in