Abstract Detail

Systematics Section / ASPT

Peterson, Paul M. [2], Columbus, J. Travis [1], Refulio-Rodriguez, Nancy F. [1], Cerros-Tlatilpa, Rosa [1], Kinney, Michael S. [1].

A phylogeny of the Muhlenbergiinae (Poaceae: Chloridoideae: Cynodonteae) based o­n ITS and trnL-F sequences.

The subtribe Muhlenbergiinae currently consists of 10 genera and 173 species almost entirely restricted to the New World.A phylogenetic analysis based o­n internal transcribed spacer (ITS) and trnL-F sequences indicates that all nine of the smaller genera, Aegopogon (4 spp.), Bealia (1 sp.), Blepharoneuron (2 spp.), Chaboissaea (4 spp.), Lycurus (3 spp.), Pereilema (4 spp.), Redfieldia (1 sp.), Schaffnerella (1 sp.), and Schedonnardus (1 sp.), are nested within a paraphyletic Muhlenbergia (152 spp).Well-supported clades include species that exclusively exhibit PCK leaf anatomy (Muhlenbergia subg. Muhlenbergia), species that have sclerosed phloem and a crown of inflated cells associated with primary vascular bundles (Muhlenbergia subg. Trichochloa), and species that usually have 3-nerved and/or toothed upper glumes (Muhlenbergia montana complex).Another fairly robust clade includes all species of Chaboissaea, Lycurus, Redfieldia, Schaffnerella, and Schedonnardus with Muhlenbergia wrightii.Muhlenbergia ramulosa consistently appears to be the basal member of the group and not closely associated with other members of the Muhlenbergiinae.The most parsimonious solution, that also involves the least number of nomenclatural changes, is to recognize all species within Muhlenbergia.A revised subgeneric classification will be presented.

1 - Rancho Santa Ana Botanical Garden, 1500 North College Avenue, Claremont, California, 91711-3157, USA
2 - Smithsonian Institution, Department of Botany, MRC166, National Museum of Natural History, P.O. Box 37012, Washington, DC, 20013-7012, USA

Keywords:
Chloridoideae
Cynodonteae
ITS
Muhlenbergiinae
phylogeny
Poaceae
trnL-F.

Presentation Type: Paper
Session: 20-8
Location: Cottonwood B (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 3:45 PM
Abstract ID:38