Found but lost? The short-lived success of Crataegus coccinea L. (Rosales: Rosaceae) in north-eastern Sicily (Italy)

Two exsiccata sampled at the end of the 19th century, and wrongly identified as Pyrus torminalis or Sorbus torminalis in the herbarium of Francesco Tornabene at Catania, belonged to a woody species never reported to occur in Sicily, Crataegus coccinea. This hawthorn, native to eastern North America, grew in two different sites located on the foothills of Mt. Etna. These records are of interest because they represent the first and only ones concerning the occurrence of this species outside botanic gardens in southern Europe. Never observed by the botanists who explored Sicily over the following 130 years, C. coccinea has probably experienced a short period of success as an ornamental plant cultivated in public and private gardens. The available information does not allow us to establish with certainty whether this species was fully naturalised in the Etnean territory in the past or not. C. coccinea should therefore be regarded as a dubious alien plant for Sicily. In the following decades this hawthorn was unable to become established, probably because of the severe constraints of fully Mediterranean climatic conditions.