Hedenäs L.1, Hedderson T.2, Kuznetsova O.I.3 , Ivanova E.I.4, Ignatov M.S.3,5 2019. Orthothecium lapponicum: a disjunctive Circum-Holarctic species // Arctoa. Vol. 28: 159–166 [in English].
1 – Swedish Museum of Natural History, Department of Botany, Box 50007, SE-104 05 Stockholm, Sweden; e-mail: email@example.com
2 – Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Private Bag, 7701, Rondebosch, South Africa; e-mail: firstname.lastname@example.org
3 – Tsitsin Main Botanical Garden, Russian Academy of Sciences, Botanicheskaya Str., 4, Moscow 127276 Russia; e-mail: email@example.com
3 – Institute for Biological Problems of Cryolithozone of Siberian Division of Russian Academy of Sciences, 41 Lenin ave., Yakutsk, 677000, Russia ; e-mails: firstname.lastname@example.org
5 – Lomonosov Moscow State University, Faculty of Biology, Moscow 119234 Russia; e-mail: email@example.com
Keywords: Bryophytes, biogeography, phylogeny, taxonomy
ABSTRACT. Orthothecium lapponicum, considered by many authors as a mere infraspecific taxon of the widespread O. chryseon, was subsequently shown to be a morphologically distinct species. Initially known only from the mountains of Northern Sweden, subsequent investigations revealed its occurrence also in Spitsbergen. Here we document its further distribution on Ellesmere Island in Canada, and in the Verkhoyansk and Chersky Mountains of Yakutia. Molecular phylogenetic analysis of the nuclear ITS region showed that specimens of Orthothecium lapponicum from Europe, Asia and North America are fully identical and highly supported as a discrete clade in Bayesian and maximum parsimony analyses, supporting its status as a good species. Descriptions and illustrations are given in order to facilitate further discovery of the species, although the very restricted range of the species seems to be real, and not simply an artifact of undercollecting or lack of recognition.