Wood Anatomy of Berberidaceae: Ecological and Phylogenetic Considerations

Qualitative and quantitative data are presented for 21 collections of Berberis and one each of Epimedium, Jeffersonia, and Nandina. Most species of Berberis have large numbers of narrow vessels ~ixed with vasicentric tracheids. Scalariform perforation plates are reported here only for Epimedium, m wh1ch they are occasional. Berberidaceae have living fibers (Berberis), fiber-tracheids plus living fibers (Nandina), or tracheids (Jeffersonia) as imperforate tracheary elements. Axial parenchyma is reported here for Jeffersonia and one species of Berberis. Previous reports of axial parenchyma in Berberis and Nandina likely refer to undivided living fibers, mostly intermixed with vessels, which are slightly shorter and with thinner walls and larger pit apertures than living fibers elsewhere in the wood. Woods of Berberis and other Berberidaceae are remarkably xeromorphic. The wide, tall rays of Berbendaceae, other than Jeffersonia, resemble rays of Clematis (Ranunculaceae) and other Ranunculiflorae. In dimensions, these rays suggest herbaceousness, but abundance of procumbent cells in these rays is not juvenilistic. No consistent differences in wood separate the subgenera Berberis and Mahonia of Berberis: although the two subgenera differ modally in several respects. Wood anatomy of Nandma IS very similar to that of Berberis, and segregation of Nandinaceae is unwarranted on the basis of wood anatomy.