Rubus is a large, critical genus in Britain and Ireland, containing many species which are closely related and difficult to identify. In the most recent monograph (Edees & Newton 1988) there are c. 325 named taxa, but perhaps another 200 or more locally-distributed forms remain undescribed or unrecognised.
Identification requires an experienced botanist who specialises in Rubus (usually called batologists, after batos = berry). Although many species can be named with experience in the field, it is often necessary to collect material to confirm identity by matching against known material held in herbaria. The main tool for studying the genus is therefore a herbarium collection. Additional identification problems arise from the occasional occurrence of hybrids where vigorous bramble growth has resulted from coppicing, felling or other disturbance, and the fact that bushes of different species often grow intermingled, making collection of representative material of the individual species difficult.
A catalogue of the 10,921 Rubus specimens named to species has been compiled. We have approximately the same number of specimens named to Series only, or without names. The catalogue gives brief details summarized from the labels and in many cases there is more detailed information available on the sheets themselves.» Rubus catalogue
The Rubus collection is one of the most important collections held in the herbarium. The collection is of international importance in its own right for five main reasons. • It is one of the major British reference collections for naming species. It contains around 15,000 specimens representing almost all of the 325 named British and Irish species, and a small collection from the European mainland.
The collection contains type specimens of at least 101 species. Type specimens are priceless assets for solving taxonomic and nomenclatural problems, and provide definitive sources of reference. When a new species is described a type specimen is assigned to that name which then remains linked to that particular specimen for ever.
The collection includes the herbarium of E.S. Edees (c. 7,500 specimens). Edees was, until his death in1988, one of the two leading bramble experts in Britain, Rubus referee for the Botanical Society of the British Isles, and author of the standard monograph describing the British and Irish species (Edees & Newton 1988). The Edees herbarium allows us to link his book to the specimens he worked on. His collection contains material from all parts of the British Isles, either collected by him or by those who submitted material for naming. It contains type material of many of the 35 new species he authored or jointly authored.
The collections are regularly worked on and updated by experts, including A. Newton the current British expert. As the taxonomy of brambles continues to be revised, it becomes apparent that the maintenance and continued use of specimens for reference is a necessity, and the collection was extensively revised during 1997 and 1998.
It contains a significant historical component including collections of several important bramble workers. There are a large number of specimens from the main period of botanical interest in critical groups towards the end of the 19th and the early part of the 20th century. In addition to the personal herbarium of W.A. Shoolbred and part (especially Welsh material) of H.J. Riddelsdell's collection, there is a complete Set of British Rubi. The Set was issued between 1892 and 1897 to botanists working on brambles so that they all had standard reference material to work from.