Sawtell, Wayne , Starr, Julian .
A systematic revision of the Carex nardina complex (Cyperaceae).
The Carex nardina complex consists of one to three species (C. nardina, C. hepburnii, C. stantonensis) and up to six taxa of unispicate arctic-alpine sedges (Cyperaceae). Since C. nardina was first described in 1839 the precise number and rank of taxa within the complex has been uncertain due to conflicting descriptions and a lack of consistent characters for separating taxa. Initial DNA phylogenies using the cpDNA gene matK suggested that the complex was nested within Carex section Filifoliae and sister to C. elynoides, a species often confused with C. nardina and sympatric with it in the western North American cordillera. As C. hepburnii and C. stantonensis possess several characters that are intermediate between C. nardina and C. elynoides, such as staminate spike length and achene length, the hypothesis that they and other infraspecific taxa may be hybrids was tested first. The results of morphometric and anatomical analyses of the putative parents and their supposed hybrids uncovered unsubstantial evidence for hybridization; further analyses were thus focused on the circumscription of taxa within the complex. Using protologues and the circumscriptions of taxa by various authors, no consistent qualitative or quantitative characters could be found to segregate taxa despite extensive analysis of the morphology, fruit epidermal silica bodies, anatomy and genome of complex members. This study therefore suggests that the Carex nardina complex consists of a single, variable species, Carex nardina, widely distributed in the arctic and western cordillera of North America with populations in north-eastern Russia, north-western Scandinavia and Iceland.
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1 - University of Ottawa, Biology, Room 160, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N6N5, Canada
2 - University of Ottawa, Biology, Room 286, Gendron Hall, 30 Marie Curie, Ottawa, ON, K1N6N5, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: Franklin B/Hyatt
Date: Monday, July 9th, 2012
Time: 2:30 PM