Although ranked globally secure (G4) in the NatureServe database (2009), Dirca palustris is recognized as imperiled (S2) and critically imperiled (S1) in Florida and North Dakota, respectively, where the southernmost and northernmost populations occur.
Noteworthy phenotypic differentiation of populations within the accepted range for Dirca palustris has been illustrated already by Floden and Mayfield (2006) and Peterson et al.
Because ISSRs have been used for both species- and population-level studies within the genus Dirca (Schrader and Graves, 2004; Graves and Schrader, 2008), we used them to study genetic variation within and among geographically disparate populations of Dirca palustris.
Our goal was to test the hypothesis that gene flow among populations of Dirca palustris was historically limited, and not the product of more recent fragmentation, by characterizing phenotypic and genetic variation within and among five natural populations and relating the observed variation to the environment and geography.
Intervascular pit pairs in woods of Gnidia caffra, Dirca palustris, and two species of Pimelea were observed with both light and scanning electron microscopy.
1 is an overall, radial longitudinal view of a water-conducting cell or vessel member in the wood of Dirca palustris.
5), and for the most part, Dirca palustris does not, although sometimes very small amounts of vesturing (best described as obscure) can be observed (Fig.
The prevailing underwoods were: Dirca palustris
(moosewood), Acer spicatum (mountain maple), Viburnum lantanoides (hobblebush), and frequently Taxus baccata, var.