AbstractA revision of the genusAndreaeain the British Isles includes eleven species, three subspecies, and two varieties:A.nivalisHook.,A. blyttiiSchimp. (new to region),A. erassinerviaBruch (of questionable occurrence),A. frigidaHub.,A. rothiiWeb.&Mohr ssp. rothii, A. rothiissp.faleata(Schimp.) Lindb. (=A. huntiiLimpr.),A. megistosporaB. murt. ssp.megistospora, A. alpinaHedw.,A. sinuosaB. Mufr.,A. mutabilisHook. f.&Wils. (new to Northern Hemisphere),A. rupestrisHedw. var.rupestris, A. rupestrisvar.papillosa(Lindb.) Podp., andA. alpestris(Thed.) Schimp. Material from the British Isles previously identified asA. erassinerviaand much of the material previously identified asA. rothiissp.rothiiis redetermined asA. rothiissp.falcata.