ALLERGENS IN THE PARK AND GARDEN FLORA OF SICILY

Abstract

The ornamental flora of parks and gardens, as we know, generally includes high proportions of exotics. In Italy it arose from Renaissance on and increasingly enriched up to include a large proportion of exotics native to countries under Mediterranean and temperate climates. Similarly the garden flora of Sicily has a large number of mostly Mediterranean and subtropical exotics. Even if very similar on the whole, these floras differ in some floristic, biological and ecological features. Indeed, several succulent families and genera that are rare or missing in Italy are frequent in Sicily, but plants from temperate regions are almost absent in the island. As regards the allergenic patterns referring to pollinosis, there are several aspects to be taken into account: In particular, native ornamental plants in Sicily often have flowering period and pollen emission early than in Italy; besides for alien plants occurring only in Sicilian gardens, the relevant allergenic properties are deduced from literature sources concerning the countries of origin. Therefore, pollen bulletins weekly spread by Italian networks (POLLnet) are not suitable for Sicily which, apart from some old and incomplete data, is presently not covered. Nevertheless, despite the lack of a continuous flow of data, a calendar of the pollen emissions in some urban areas can be programmed. Indeed, taking into account the city of Palermo, where 23 public gardens have been floristically inventoried and mapped, the calendar of each single garden can be obtained using the comprehensive garden floristic list fitted out with the relevant allergenic data now complete for Sicily. In particular, with respect to the sole woody fraction (the whole Sicilian garden flora includes about 740 specific taxa), such list consists of 406 specific taxa, belonging to 191 genera of 83 families. Among these species, 265 - including 182 exotics - are allergenic. The most inclusive group are the conifers, with 23 allergenic species; among the families, the Oleaceae with 11.