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364 P. MAZZOLA, R. SCHICCHI & S. CICCARELLO

or to circumscribed areas of Sicily that were islands
in the past. These latter partly correspond to the flo-
ristic subdivision provided by Brullo et al. (1995).

Besides distribution outlines, for each taxon,
when possible, karyological data, mostly deduced
from literature, are also taken into account. Nomen-
clature follows Giardina et al. (2007).

SICILY

The above quoted 322 exclusive endemics, Figure 1. Orchis commutata, a tetraploid vicariant of O.
mark a significant evidence of the whole Sicilian tridentata; distribution: Sicily.
archipelago insularity; while in the total of 502
there are also included other taxa whose ranges pani. The western part of this palaeo-island is cha-
show contacts happened with other Mediterranean racterized by several other endemic geophytes.
areas. In addition to such general information, Among these, O. pallida Raf. (Fig. 2) occurs bet-
from the analysis of single taxa some evidence on ween the Madonie Mountains (here very rare) and
their actual insular endemic condition is deduced the mountains around and south of Palermo, espe-
and, besides, on the relevant evolution processes. cially in the Monte Busambra zone, and in the
In particular, those endemics exclusive to Sicily Monte S. Calogero west of the town of Termini
and there spread everywhere show their insular Imerese, one of past coastal islands having been in-
condition. corporated in the northern Sicilian littoral (Rai-
mondo et al., 2001).
Among these there are several orchids like
Ophrys oxyrrhynchos Tod., O. lunulata Parl. and In western Sicily, Oncostema ceruleum (Raf.)
Orchis commutata Tod. (Fig. 1) which, occurring Speta occurs with a range similar to O. pallida, to-
throughout the region, is likely a good example of gether with many other (not only) exclusive ende-
a neo-endemic tetraploid (2n = 84) vicariance with mics like Colchicum gussonei Lojac. (related to C.
respect to O. tridentata Scop., diploid (2n = 42), cupanii Guss. and there included by Giardina et al.
whose range covers Central and S-Europe up to the (2007)), and several endemic Gagea species such
region of Calabria (Mazzola, 1984) where is its sou- as G. busambarensis (Tineo) Parl., G. longifolia
thernmost distribution limit lies. O. tridentata is in- Lojac., G. sicula Lojac. G. lacaitae A. Terracc., G.
deed missing in Sicily. Apart from some slight ramulosa A. Terracc. that virtually refer to the
differences in size, these two taxa are almost indi- above mentioned western side of the northern Mid-
stinguishable. O. lunulata (2n = 36) occurs throu- dle Pleistocene island, i.e. the District Drepano-Pa-
ghout Sicily, but it is more frequent in the extreme normitano by Brullo et al. (1995). Gagea also
SE, the Iblei Mountains (the Iblei District, accor- occurs on the Madonie Mountains with several spe-
ding to Brullo et al., 1995), where O. biancae (Tod.)
Macch. (2n = 36), O. caesiella P. Delforge, and se-
veral other more or less distinct taxa belonging to
the O. lutea and O. fusca groups occur frequently.

The occurrence of these geophytes, together
with a special terrestrial vertebrate palaeofauna, and
other local endemic or rare plant species (Brullo et
al., 1995) show that the Iblei Mountains were an is-
land during the Middle Pleistocene (Guglielmo &
Marra, 2011). In that period, the rest of the present
Sicily was in part submerged, and in part, nor-
thwards, occupied by another large island, including
the mountainous ranges between Messina and Tra-