Abstract Detail

Systematics

Naczi, Robert [1], Oommen, Ansel [2], Roberts, Mari [1], Dorey, Jenna [1], Calie, Patrick [3], Knapp, Wesley [4], Hardy, Sarah [1], Plunkett, Gregory [5].

Phylogeny of Rhynchospora section Plumosae (Cyperaceae) based on morphologic and molecular data.

Rhynchospora section Plumosae (Cyperaceae) is a clade of 6−7 beaksedge species occurring in the eastern and southeastern U.S.A., Central America, and the Caribbean. Several of the species have narrow geographic ranges and are of conservation concern. All of the species occur in sunny, nutrient-poor, sandy or peaty habitats such as open pinelands and savannas. Morphologic synapomorphies for members of section Plumosae include plumose perianth bristles bearing trichomes that are twisted when dry, fruit bodies with epicuticular wax, and distal portions of achene bodies sparsely denticulate. Phylogenetic analyses of anatomic, micromorphologic, and macromorphologic data yield fully resolved relationships for the species. Some of these relationships are weakly supported, due to few phylogenetically informative morphologic characters. The morphologic data strongly support two clades within Plumosae, the R. oligantha clade and the R. plumosa clade. Preliminary analyses of sequence data from nuclear (ETS, ITS) and plastid (rpl32-trnL) markers yield fully resolved relationships for the species, though many relationships are weakly supported due to low sequence divergence for the markers. These molecular analyses recover the R. oligantha clade, but the other species (the R. plumosa clade of the morphologic analysis) are paraphyletic. Ongoing work with other markers may improve support for the molecular analyses (e.g. we are currently working with matK and ndhF).

1 - New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458-5126, USA
2 - New York Botanical Garden, 2900 Southern Blvd., Bronx, NY, 10458-5126, United States
3 - Eastern Kentucky University, Biological Sciences, 521 Lancaster Ave., 3238 SCIBD, Richmond, KY, 40475, USA
4 - North Carolina Natural Heritage Program, 176 Riceville Rd, Asheville, NC, 28805, United States
5 - New York Botanical Garden, Cullman Program For Molecular Systematics, 2900 Southern Blvd., Bronx, NY, 10458, United States

Keywords:
Rhynchospora
Rhynchospora section Plumosae
phylogeny
beaksedge
conservation
nutrient-poor
Cyperaceae.

Presentation Type: Oral Paper
Session: SYS1, Systematics I: Land plants, Gymnosperms to Rosids part 1
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 2:45 PM
Number: SYS1006
Abstract ID:741
Candidate for Awards:None