DIVERSITY OF SMYRNIUM PERFOLIATUM (APIACEAE) IN SICILY

Smyrnium L. is an Eurasian genus of the family Apiaceae, including about 20 species. In the Italian flora, it is represented by 3 taxa also occurring in Sicily. These are: Smyrnium olusatrum L., S. perfoliatum L. and S. rotundifolium Mill. (1, 2). The last one has also been treated at the rank of subspecies under S. perfoliatum [S. perfoliatum subsp. rotundifolium (Mill.) Hartvig] (3, 4) or as a mere variety (5). Smyrnium olusatrum, often associated to nitrophylous habitats, unlike the other two, occurs throughout most of the Island. Smyrnium perfoliatum occurs in the underwood of deciduous Quercus sp. pl. or of Fagus sylvatica L. woods, in the submontane and montane belts of the Nebrodi mountains. Smyrnium rotundifolium is instead common in some less mesophylous environments like thermophylous open woodlands of central and western Sicily. In this sector of the island, the populations of the Madonie and of the Montains around Palermo referable to S. perfoliatum diverge for both morphological and ecological characteristics. Indeed, plants corresponding to S. perfoliatum subsp. perfoliatum occur only in the underwood of Quercus and Fagus woods in the Nebrodi mountains, under mesophylous conditions; dissimilar forms that are rather intermediate with respect to S. rotundifolium instead occur in C-W Sicily (Madonie and Mounts of Palermo). The study of the phenotypic characters, in particular of the leaf, makes possible to clearly distinguish these populations that, therefore, represent a taxonomically and perhaps even chorologically critical case, since similar plants of Greece have been described as S. rotundifolium var. ovatifolium Halàksy (6). Then, the latter taxon, today overridden, in the light of the Sicilian case should be re-evaluated.