Ricerc@Sapienza

Species identification within the species complex
of Q. pubescens is a well-known taxonomic challenge
among European botanists. Some of the specific
pubescent oak binomials currently accepted in various
European floras and checklistswere originally described
in Sicily and southern Calabria. As a consequence,
several species belonging to the pubescent oaks group
(Q. pubescens, Q. amplifolia, Q. congesta,
Q. dalechampii, Q. leptobalana and Q. virgiliana) are
reported in the taxonomic and phytosociological literature.
To verify whether it was possible to associate a
diverse set of morphological characters with each of
these different taxa, thirteen natural populations of pubescent
oak from Sicily and southern Calabria were
sampled. A total of 391 trees, 3,887 leaves and 1,047
fruits were collected. Overall, 28 morphological characters
of oak leaves and fruits were statistically analysed
using univariate and multivariate procedures. The results
showed that neither the groups of morphological
diversity identified by cluster analysis, nor those obtained
by our expert identification through the use of analytical
keys, matched with the current taxonomical
frameworks as proposed by the most recent floras and
checklists. Nearly all of the morphological characters
considered displayed a more or less continuous trend of
variation, both within and among populations. In the
light of these findings it seems unlikely that more than
one biological species of pubescent oak occurs in Sicily
and southern Calabria.