Abstract Detail

Systematics

Dorey, Jenna [1], Naczi, Robert [1], Hoshino, Takuji [2].

Systematics of Forest Sedges Carex section Laxiflorae (Cyperaceae).

Carex section Laxiflorae includes some of the most common sedges in forests of eastern North America, as well as several narrowly endemic species. These sedges are ecologically important in the forest understory, especially in the prevention of soil erosion. The section is currently comprised of 16 species in North America, but is in great need of taxonomic revision since several species appear to contain previously undocumented diversity, and the sectional boundaries are unclear. The phylogenetic study with most thorough sampling of Carex indicates that the Laxiflorae are part of a clade that also includes sections Paniceae and Bicolores, and contains approximately 50-60 taxa from Asia, Europe, and North America. This clade that includes section Laxiflorae appears to have two centers of diversity – one in eastern North America, and one in Eastern Asia. We, therefore, hypothesize that this clade was once widespread throughout a continuous forest in the Northern Hemisphere and that the present-day patterns of diversity are due to species radiations on both continents. The goals of this research are to test the monophyly and ascertain the sectional limits of Laxiflorae, to delimit and circumscribe species within difficult complexes of Laxiflorae s.s., and to view the biogeographic patterns that led to the present distribution of sections Laxiflorae, Paniceae, and Bicolores. Here, we present results of ongoing field and herbarium work, morphometrics, and molecular systematics. A maximum likelihood reconstruction of 6 gene regions in over 100 individuals of about 65 taxa from North America, Europe, and Asia recovered section Laxiflorae as paraphyletic, with a predominantly North American clade separate from a predominantly Eurasian clade. Both molecular and morphological analyses also offer support for undescribed taxa in North America. These important results will lead to a revised classification of section Laxiflorae, and description of new taxa.

1 - The New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458, USA
2 - Okayama University Of Science, Kitaku, Ridai-cho, 1-1, Okayama, 700-0005, Japan

Keywords:
Carex
phylogeny
Cyperaceae
biogeography.

Presentation Type: Oral Paper
Session: 14, Systematics I: Basal Dicots, Monocots & Rosids
Location: Sundance 1/Omni Hotel
Date: Monday, June 26th, 2017
Time: 3:00 PM
Number: 14007
Abstract ID:190
Candidate for Awards:None