Conservation of Britain's biodiversity: the case of Hieracium cyathis (Asteraceae) and its relation to other apomictic taxa

Hieracium cyathis (Ley) W. R. Linton (Asteraceae), Chalice Hawkweed, is a rare species endemic to Britain. It is a distinct member of Hieracium Section Oreadea , characterized by a short acladium and out-curved tips to the phyllaries. Historic records and current field survey indicate it has occurred in two localities in SW England and seven in South Wales. It is still present in all sites except for one Welsh locality, is significantly threatened at Cheddar Gorge, and two Welsh sites have only three plants each. Comparative morphology, cultivation experiments and amplified fragment length polymorphism (AFLP) analysis do not support the reported differences between material from SW England and Wales. AFLP analysis showed that every plant in the field was genetically similar but different, and minor genetic variation was found in one progeny array. It is a triploid (2 n  = 27) with apomictic seed production, and 26% potentially viable pollen. It qualifies as 'Near Threatened' under the 2001 IUCN threat criteria. General guidelines for conservation of microspecies of Hieracium are discussed.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 669–680.