Summarises information on voucher specimens of rare and endangered plants in the British and Irish herbarium at Liverpool Museum. Species chosen for inclusion are those to be treated in the forthcoming edition of the Red Data Book for British Vascular Plants (Wigginton) together with species included in the second edition which are not given a full listing in the new edition. Specimens from the Republic of Ireland, Northern Ireland, the Isle of Man and the Channel Islands as well as Great Britain have all been catalogued.