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Roger Bull

    Roger Bull

    The Arctic ecozone is undergoing rapid and major change in response to climate change. Establishing a baseline of current Arctic vascular plant diversity and distribution is necessary to be able to track changes in species composition... more
    The Arctic ecozone is undergoing rapid and major change in response to climate change. Establishing a baseline of current Arctic vascular plant diversity and distribution is necessary to be able to track changes in species composition over time due to climate change. Here, we report the results of a floristic study of vascular plant diversity of Katannilik Territorial Park and Kimmirut and vicinity on southern Baffin Island in the Canadian Arctic Archipelago, Nunavut, Canada. The study area is located within Circumpolar Arctic Bioclimate Subzone D. The study is based on a dataset comprising 1571 collections from the study area gathered over the last century, including 838 collections we made during fieldwork in 2012. We present the results in an annotated checklist. The vascular plant flora of the study area comprises 34 families, 98 genera, 210 species, three nothospecies, and seven infraspecific taxa. We recorded 190 species, five infraspecific taxa, and two nothospecies from Kata...
    ... Fig. 1). Four subspecies— V. c. celata, V. c. orestera, V. c. lutescens, and V. c. sordida— are recognized on the basis of differences in plumage, molt patterns, and size (Sogge et al. 1994, Pyle 1997). ... 1985, Sogge et al. 1994 ...
    ABSTRACT Phylogenetic analyses within Poaceae tribe Poeae subtribes Puccinellinae (= Coleanthinae), Phleinae, Poinae s.l. (including Alopecurinae), and Miliinae (PPAM clade), revealed that one species formerly placed in Poa represents a... more
    ABSTRACT Phylogenetic analyses within Poaceae tribe Poeae subtribes Puccinellinae (= Coleanthinae), Phleinae, Poinae s.l. (including Alopecurinae), and Miliinae (PPAM clade), revealed that one species formerly placed in Poa represents a new monotypic genus belonging to subtribe Poinae s.l., Dupontiopsis gen. nov., D. hayachinensis comb. nov. (based on Poa hayachinensis), endemic to wet, gravelly, serpentine, alpine habitats in northern Japan. This genus forms a strongly supported clade (DAD) with two circumarctic Poinae genera, Arctophila and Dupontia, in phylogenetic analyses of plastid and nuclear ribosomal DNA sequence data. Both morphology and DNA sequence analyses provide support for D. hayachinensis as a lineage distinct from either Arctophila or Dupontia, with moderate DNA support for a position as sister to these two genera. Dupontiopsis resembles these other monotypic genera in its several-flowered spikelets, lemmas usually 3-nerved, with frequently awned attenuate scarious apices (as in Dupontia) and calluses with a crown of hairs around the base of the lemma, but differs in its keeled lemmas, scabrous palea keels, glumes shorter than the first lemma. Our investigation suggests that the most recent shared ancestor of the DAD clade evolved from a single hybridization event, as a hexaploid, probably in western Beringia. The probable parentage of the ancestor is considered to be within the Poinae-Alopecurinae clade excluding Poa. We provide evidence for possible secondary hybridization and introgression of duodecaploid Dupontia fisheri with Puccinellia. A key to perennial genera of PPAM with hairy calluses, and a supplemental table of morphological characters in the genera accepted in PPAM are provided.