An historic herbarium: what can it tell us about the changing flora of Britain in the 20th and 21st centuries? RICHARD G. JEFFERSON
Herbarium sheet of Phleum arenarium (Sand Cat’sai t ) l coect l edbyPetereffer J sofrn ‘san mo ddues, n an lL dudn,o N.Wales’,enuJ 2 1948.
O
ver the last eight decades, the native flora of Great Britain has undergone substantial change with some species extinctions but with many more species having suffered from contractions in range and/or in the number and size of their populations. The 20th century was a period of heightened extinctions in the vascular flora at different geographical scales with seminatural habitat specialist species being particularly extinction-prone (Stroh et al., 2019; Walker, 2003; Walker & Preston, 2006; Walker et al., 2017). This article describes a small herbarium of vascular plants collected and assembled during the 1940s and 1950s and, with the assistance of the BSBI Distribution Database (DDb), explores what can be concluded with respect of changes in the British flora over the last 80 years or so.
Background to the herbarium
Between 1943 and 1956, my father, the late Peter Jefferson (PJ), put together a small herbarium of flowering plants from a variety of localities across Great Britain. In 2018, the information
in the herbarium was collated and documented by the author prior to donation to the Natural History Museum, London (BM). This provided an opportunity to assess whether the information contained in the documentation of each specimen could be used to provide further insights into change in the British flora since the 1930s. By way of context, my father was a zoologist with an amateur interest in botany. He worked for the Sports Turf Research Institute at Bingley, West Yorkshire (STRI) until 1956 where he researched the effects of the impacts of earthworms on sports turf (e.g. Jefferson 1956). During this period, he resided in Bramley, Leeds. He then lectured in Zoology at Nottingham College of Technology (now Nottingham Trent University). During his stint working for STRI, he was involved in advising on the management of golf courses around the country. This enabled him to visit sites on or within the vicinity of golf courses (but by no means exclusively) and to collect plants from around Great Britain. However, specimens from West and North Yorkshire make up a significant proportion of the collection. BSBI NEWS 149 | January 2022
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