Thedifficultplantproblem
in Oxford University, Royal Botanic Gardens Edinburgh and the Natural History Museum, though these are somewhat out of date taxonomically. Local museum herbaria are rarely worth looking at unless revised by an expert, and many are now managed by specialist conservators who know how to look after the specimens long term but not how to use them. Anyone studying difficult plants will need to access such herbaria. There are few computerised catalogues available to plan what to see in advance, it costs to travel and most herbaria are not open at weekends (I was guilty of this at Cardiff – I had a young family). Curators are generally helpful sending images if you know what to ask for, but there is no substitute for seeing the actual specimen when, say, looking at types of hair under a microscope. Expert opinions Once you have made a provisional identification using the literature or herbarium, confirmation
Figure 1. Part of the Taraxacum oxoniense account from the latest BSBI Handbook on Dandelions. Reproduced with permission of BSBI and John Richards.
Herbaria Herbarium collections allow comparison of species side by side and allow named vouchers to be matched against unknown material. Initially for each difficult group, it is best to focus on national collections created by, or revised by, experts as these are more likely to be named correctly and they show the development of the taxonomy with time. To be useful, the collections need to be kept up-to-date by taxonomists, for example the superb Rubus collection at the Natural History Museum has been extensively revised by the authoritative amateur David Allen over the last 40 years. When he retired from Newcastle University, John Richards gave the national Taraxacum herbarium collection to the Welsh National Herbarium, which we then curated, databased and stored (Figure 2). This is now the starting point for dandelion research in Britain; there are also good dandelion collections
Figure 2. Part of the National Taraxacum collection eht ni WelshNatal noi erH bar7; 0 2 ni mu ko l I considerably older now as a result of tackling difficupltl angrt ps. uo
BSBI NEWS 149 | January 2022
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