Senecio squalidus

Oxford Ragwort (Senecio squalidus), a Ragwort (member of the Senecio genus) from the daisy family Asteraceae, yellow-flowered herbaceous plant, native to mountainous, rocky or volcanic areas, has managed to find other homes on man-made and natural piles of rocks, war-ruined neighborhoods and even on stone walls that resemble their well drained rocky homeland at other places in the world via wind, rail and botanists. The travels and discriminative tendencies regarding propagation of this short-lived perennial, biennial, or winter annual make it a good subject for studies of the evolution and ecology of flowering plants.

Common names

Description

Like all members of the large Asteraceae family, Senecio squalidus has a flower head (or capitulum) joined to the plant stem by bracts and what look like single flowers are actually a cluster or inflorescence with each petal or corolla being its own flower, or floret, possessing its own stamen and capable of producing the specialized seed of the family Asteraceae -- the parachute-like achene.^[7]

Oxford Ragwort is a short-lived perennial, a biennial, or a winter annual and grows in a branched straggling form to between 1.5 feet (0.5 m) and 3.3 feet (1 m) depending on conditions. S. squalidus prefers dry, disturbed places, cultivated and waste ground, walls and railway banks,^[8]^[3] flowering from March^[9] to December^[8] and reproduces from seed.^[3]

History

This Senecio was introduced into Britain via Francisco Cupani and William Sherard in the years of their visit 1700, 1701 and 1702 from Sicily^[15] where it lives as a native on volcanic ash^[13] to the Duchess of Beaufort's garden at Badminton. Later a transfer of the genetic material to the Oxford Botanic Garden by the "Horti Praefectus" (the title still given to the head gardener at the Oxford Botanic Garden^[16]) Jacob Bobart before his death in 1719^[17] (which is also the same year that Bobart the Younger retired as Horti Praefectus^[16] and 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^[9]) and many of the stone walls around the city of Oxford. This gave the plant its common name, "Oxford Ragwort".^[18]

Carolus Linnaeus first described Senecio squalidus^[19] in 1753 and there is a dispute as to whether the material came from the Botanic garden or from walls in the city and the taxonomy for this species is further complicated by species with a similar morphologically similar taxa on continental Europe.^[17]

James Edward Smith officially identified the escaped Oxford ragwort with its formal name Senecio squalidus in 1800.^[17]

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 home.^[9]

Recently, this and other Senecio 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:

Distribution

Senecio squalidus rows on scree in mountainous regions of native range,^[3] and earned its common name Oxford ragwort for its willingness and ability to grow in similar habitat elsewhere in the world.^[17]