Field Event Reports

Tuesday 14 February: A visit to Oxford University Herbaria

Our visit was guided by Dr Stephen Harris

Leader: Dr Stephen Harris, Druce Curator of the Oxford University Herbaria

Forgoing romantic Valentine dinners, fourteen members gathered at Oxford University Department of Plant Sciences for a visit to the Herbarium led by the Curator, Dr. Stephen Harris. The theme was "The Oxfordshire Flora from 1660 to the Present Day", and prior to our arrival Dr. Harris had laid out a selection of specimen pages together with photos and memorabilia of past Keepers and others who had contributed to our present knowledge.

In his introduction, Dr. Harris mentioned that dried plant collections first started in Bologna in Italy in the 15th century, and there were now 300 million specimens in herbaria worldwide, of which Oxford holds one million including 200,000 British specimens. The Oxford collection was started by Jacob Bobart the Elder in 1642, and we were shown a page of specimens from his time. The presentation was as much about personalities as species, and Dr. Harris described the work of the two Bobarts, Dillenius, whose interest lay in mosses and lichens (we were shown a page of his lichen specimens mounted on original 17th century wallpaper), Sibthorp and more recently George Claridge Druce, who bequeathed his collection of British specimens to the herbarium on his death in 1932. Druce's work centred mainly on Oxfordshire species, including the Shepherd's Purse which was named Bursa druceana after him, although it is now more widely known by its synonym, Capsella bursa-pastoris. We were shown Druce's specimen of this species. His main plant of interest, however, was the Oxford ragwort, Senecio squalidus. This was introduced to the Oxford Botanic Garden from Mt. Etna in Sicily in the early 18th century and spread along walls within the city. On the arrival of the railways in the 19th century it found clinker beds to its liking and thereby spread throughout the country. Recent research has shown that the plant known today in Britain is in fact a hybrid of two species that live on the upper and lower slopes respectively of Mt. Etna, the hybrid colonising the middle zone. This raises the possibility that the two parent species may have been introduced instead of or as well as the hybrid, resulting in a similar hybridization in Oxford to that which took place in Sicily.

Dr. Harris was warmly thanked at the end of a fascinating and intriguing evening.

Michael Bloom

The members comprising the group were:
Graham Bateman, Diane June Rockett, Peter Rockett, Lucille Savin, John Killick, Nigel Gregory, Caroline Gregory, Sally Gillard, Dave Fielding, Michael Bloom, David Lloyd, Felicity Jenkins, Sue Morley, John Thacker