Saarela, JM, LJ Gillespie, LL Consaul, JR Starr, RD Bull, PC Sokoloff. 2011. DNA barcoding the vascular plant flora of the Canadian Arctic. International Botanical Congress 2011, Melbourne, Australia, 17-29 July 2011. [e-poster]

2. Cyperaceae Poaceae Papaveraceae Ranunculaceae Onagraceae Saxifragaceae Brassicaceae Haloragaceae Parnassiaceae Elaeagnaceae Asteraceae Betulaceae Rosaceae Salicaceae Fabaceae Plumbaginaceae Montiaceae Polygonaceae Caryophyllaceae Orobanchaceae Plantaginaceae Lentibulariaceae Gentianaceae Ericaceae Primulaceae Polemoniaceae Diapensiaceae Menyanthaceae Apiaceae Campanulaceae Valerianaceae Caprifoliaceae Tofieldiaceae Potomogetonaceae Juncaginaceae Orchidaceae Liliaceae Typhaceae Linaceae Progress: We have generated DNA barcode data from 1530 individuals representing some 479 Arctic taxa (409 species and 72 infraspecific taxa) in 39 families. An additional 1486 samples from 234 taxa have been selected for amplification and sequencing, or have been successfully sequenced for one of the two barcoding loci. Once complete, these data will represent some 3000 rbcL + matK barcode sequences for 713 (70%) of the estimated 1013 vascular plant taxa in the Canadian Arctic. MatK + rbcL DNA barcode data distinguish Arctic plant families with strong support, but most deeper and shallower lineages are more poorly supported. monocots eudicots Neighbor-joining tree of 1530 concatenated matK and rbcL sequences. Bootstrap support: 100% 90-99% 80-89% 70-79% <70%

3. Draba Arabis Eutrema Braya Cochlearia Erysimum Transberingia Descurainia Physaria Parrya Cardamine Arabidopsis matK + rbcL DNA barcodes can distinguish species and genera in some Arctic plant families Ericaceae Brassicaceae Cyperaceae - Carex and Kobresia R. Bull Orthilia secunda Pyrola grandiflora Arctous rubra Andromeda polifolia Vaccinium uliginosum Vaccinium vitis-idaea Harrimanella hypnoides Cassiope tetragona Empetrum nigrum Loiseleuria procumbens Phyllodoce caerula Rhododendron tomentosum Rhododendron lapponicum Carex canescens/Carex marina Kobresia myosuroides Kobresia simpliciuscula Carex aquatilis var. minor/ Carex subspathacea Carex supina Carex disperma/Carex rariflora Carex podocarpa/Carex spectabilis Carex maritima Carex bigelowii s.l. Carex norvegica Carex ursina Carex nardina Carex rupestris Carex garberi/ Carex bicolor Carex vaginata Carex atrofusca Carex scirpoidea subsp. scirpoides Carex glacialis Carex saxatilis/Carex membranacea Carex rotundata Carex holostoma Carex concinna Carex krausei Carex petricosa subsp. petricosa Carex capillaris subsp. fuscidula Carex fuliginosa subsp. misandra Carex lachenalli Kobresia sibirica Barcode data can distinguish most Arctic species of Carex and Kobresia, many of which are distantly related. However, bootstrap support for most species lineages is low, as they are distinguished by few characters. Ericaceae genera are clearly distinguished with strong support, and there is informative interspecific plastid variation in genera with more than one Arctic species, including Rhododendron and Vaccinium . Barcoding works well to identify Arctic Ericaceae species because the genera have one or very few species in the Arctic . Barcode data effectively distinguish the Arctic genera of Brassicaceae, but infrageneric variation is low and most congeneric species are not distinguished, especially in the taxonomically difficult genus Draba. Thlaspi Neighbour joining bootstrap branch support: 100% 90-99% 80-89% 70-79% <70%

4. Species in some taxonomically complicated Arctic genera are not resolved with barcode data A complete species-level DNA barcode database for Arctic plants will no doubt facilitate some future ecological and systematic research on the Arctic flora, but nuclear-based barcode markers will need to be developed to identify species-specific nucleotide differences in taxonomically difficult groups with minimal plastid variation. Potentilla and allies (Rosaceae) Salix (Salicaceae) Taraxacum (Asteraceae) There is little plastid variation among Arctic species of Salix. Substitutions are present in a few individuals (as indicated by branch length variation), but these do not follow species boundaries. Sibbaldia procumbens Dasiphora fruticosa Potentilla anserina subsp. egedii Potentilla biflora/P. bimindorum Potentilla sects. Niveae & Pennslyvanicae Comarum palustre Three genera formerly considered members of Potentilla (Dasiphora, Sibbaldia and Comarum) are readily distinguished using barcode data, but Arctic species of Potentilla s.s. are not, most notably in Potentilla sections Niveae and Pennsylvanicae, in which hybridization is rampant. T. ceratophorum / T. carneocoloratum T. lapponicum / T. hyperboreum / T. ceratophorum T. ceratophorum / T. holmenianum / T. hyparcticum T. hyparcticum / T. phymatocarpum / T. holmeniaum Barcode data do not provide reliable resolution for Arctic Taraxacum species, which are native only in the Arctic in North America. Minor infraspecific variation in Taraxacum (i.e., multiple single substitutions) does not follow currently recognized species boundaries, possibly as a result of apomixis, polyploidy, hybridization and introgression, which all occur in the dandelion genus. Creative Commons: Attribution- NonCommercial-ShareAlike licence R. Bull R. Bull R. Bull R. Bull R. Bull Neighbour joining bootstrap branch support: 100% 90-99% 80-89% 70-79% <70%