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.
On each branch, we also measured the internode between the terminal and first subterminal inflorescence, the length of the thorn-like spur that arises from the terminal position on branches of Dirca (Graves, 2006), and the basal diameter of the stem that formed in 2009.
North Dakota), after leaves in the overstory had fully expanded and when Dirca palustris were similar phenologically at all sites (Table 1).
From each population we collected fully expanded leaves from 19 mature Dirca palustris selected to represent the spatial distribution of plants within the population.
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.
Although Daphne and Wikstroemia are within the same tribe (Daphneae, Table 1), so are Edgeworthia and Dirca but neither of the latter two genera possess tori (Dute et al, 1996; the present study).
Daphne with a more circular aperture has a torus, but Dirca whose aperture is of a similar circularity, does not.
1992; Ohtani & Ishida, 1976), vessel pits of Dirca and Ovidia (Record & Hess, 1943), and Aquilaria agallecha (Rao & Dayal, 1992).