Abstract Detail

Systematics Section/ASPT

Spalink, Daniel [1], Sytsma, Kenneth [2].

Phylogeny reveals a persisting polyphyly in the bulrushes (Scirpus, Cyperaceae): implications for a long-troubled taxonomy and insights into bulrush diversification.

The taxonomy of the bulrushes (Scirpus, Cyperaceae) has been troubled since Species Plantarum, in which Linnaeus described the genus as having terete spikelets, spirally imbricate scales, and 3-fid bisexual flowers. This rather loose definition of the bulrushes resulted in a large and unnatural genus, with subsequent treatments describing as many as 1672 unique taxa. Scirpus has been since redefined to include 35 temperate and boreal emergent aquatic species, and molecular studies have confirmed that most Scirpus s.l. segregates are indeed evolutionarily distinct from Scirpus s.s. However, the exact limits of the genus remain unclear and infrageneric relationships are largely unknown, preventing evolutionary analyses that would provide insight into the diversification of this group. This study seeks to assess the monophyly of Scirpus s.s. as currently defined, to clarify relationships within the genus, and investigate the biogeographic patterns of diversification that have contributed to its evolution. We utilize a 9-locus dataset (including three novel single-copy nuclear markers) to provide resolution to this clade. We demonstrate with strong support that Scirpus s.s. remains paraphyletic, and that delineating a monophyletic Scirpus will necessitate an inclusion of the genus Eriophorum (cotton-grass). Our data also imply a North American origin of Scirpus, and invoke at least three independent long-distance dispersal events that have contributed to the diversification of the bulrushes in Eurasia

Broader Impacts:

1 - University of Wisconsin-Madison, Department of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - University of Wisconsin, Department of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
Cyperaceae
Scirpus
Eriophorum
Phylogenetics
nuclear markers.

Presentation Type: Oral Paper:Papers for Sections
Session: 11
Location: Magnolia/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 2:45 PM
Number: 11006
Abstract ID:740
Candidate for Awards:George R. Cooley Award