Systematics Section / ASPT
Anderton, Laurel , Barkworth, Mary .
Glyceria occidentalis (Poaceae), G. declinata, G. fluitans, and G. plicata: are they really different?.
The presence of the European species Glyceria declinata Bréb. in North America has been questioned since 1949 when it was first reported from California. Debate has centered over whether or not this species can be reliably distinguished from the native North American G. occidentalis (Piper) J. C. Nels. Morphometric analysis was performed on European and U. S. herbarium specimens identified as G. declinata and on U. S. specimens of G. occidentalis, as well as on European specimens of G. fluitans (L.) R. Br. and G. plicata (Fries) Fries. The resulting measurements were subjected to both cluster analysis and principal components analysis in an attempt to reveal groupings, and to determine if such groupings were consistent with each other and the existing specimen identifications. These analyses did not bring to light any consistently discernible groups; rather, the measurements showed a high degree of overlap among all species. Results to date do not support recognition of more than one taxon among the specimens examined, and suggest that further genetic analysis would be of value.
1 - Utah State University, Intermountain Herbarium, Dept. of Biology, 5305 Old Main Hill, Logan, Utah, 84322-5305, U.S.A.
Presentation Type: Paper
Location: Cottonwood B (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 4:15 PM