First report of Sida rhombifolia in Italy
Sida rhombifolia (Malvaceae) has a wide distribution and although its native range is unknown, it is thought to be the Paleotropics. It has been introduced to the Americas. Throughout its range it is reported as a common weed along roadsides, urban areas, pastures and cultivated fields. During surveys conducted from 2014 to 2021 in North-Eastern Sicily (Italy), S. rhombifolia was found in five localities in the Peloritani mounts, along the coastal belt between Furnari and Rometta, near Messina. Here it colonizes disturbed habitats (roadsides, abandoned quarries and uncultivated areas) at an altitude of 0-140 m a.s.l., which have high levels of nitrates and moderate moisture levels. This is the first time that S. rhombifolia is reported from Italy. In Sicily, it is locally well established and exhibits high coverage. The stands of S. rhombifolia distributed in the North-East of Sicily are comprised of multiple individuals (ca. 50–100 for each stand). Spread can be facilitated by seed which can adhere to clothing and animals. The introduction of S. rhombifolia into Sicily was probably accidental, due to seeds carried on vehicles in an area of trade such as the Messina Strait. Alternately, it may have entered from the horticulture trade, specialized in the trade of exotic species, since the first finding was made in an area with a high human presence.
Sources
Cambria S, Crisafulli A, Giusso del Galdo G, Picone RM, Soldano A, Sciandrello S, Tavilla G (2022) First record of Sida rhombifolia L. (Malvaceae) for Italian flora: taxonomical and ecological investigation. Acta Botanica Croatica, https://doi.org/10.37427/botcro-2022-013