This Senecio was introduced into
Britain via
Francesco Cupani and
William Sherard in the years of their visit 1700, 1701 and 1702 from
Sicily where it lives as a native on
volcanic ash providing perhaps a good indication of when this species of ragwort and other
invasive species might have "escaped" and started to make their home in the greater
British Isles. The Sicilian ragwort escaped into the wild and grew in the
stonework of
Oxford colleges (with the specific mention of the
Bodleian Library Carl Linnaeus first described
Senecio squalidus in 1753, although there is a dispute as to whether the material came from the Botanic Garden or from walls in the city; the taxonomy for this species is further complicated by the existence of species with a similar morphology in continental Europe. During the 20th century it continued to spread along railway lines and found a liking for waste places and bombed sites
after World War II which have a lot in common with the
volcanic regions of its home. Recently, this and other
Senecio species and their differing tastes for
self-incompatibility and self-compatibility have been the subject of study for the purposes of understanding the evolution of plant species as the genus finds new homes and pollen partners throughout the world: • The origin of
Senecio vulgaris var.
hibernicus Syme was determined to be an
introgression of
Senecio squalidus into
Senecio vulgaris subsp
vulgaris • The dual origin of
S. cambrensis Rosser to both
Wales and
Scotland explained as being a product parenting by the
diploid S. squalidus and the
tetraploid S. vulgaris in both locations • The willingness of
S. squalidus to
hybridize with
Senecio viscosus Crisp & Jones and forms the
sterile hybrid S. subnebrodensis Simk. • The suggestion that
S. squalidus is actually a hybrid of two other Sicilian
Senecio:
S. aethnensis Jan ex DC and
S. chrysanthemifolius Poir. ==Distribution==