Native shrub species such as broom and asparagus were chosen for the experimental investigation. The study was
conducted with plants collected in the area of Motta S. Anastasia (Catania), and Mirabella Imbaccari (Catania) in the
center of Sicily (Italy), just a few km western of Catania. Those plants grow up spontaneously in the quoted sites
and have been transplanted with their root balls. Thirty plants were sampled. Table 1 lists the key features of the
examined plants.