Browsing by Author "Barker, N P"

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    A new species of Merxmuellera (Arundineae, Poaceae) from South Africa
    (1991) Barker, N P; Ellis, R P
    Merxmuellera setacea N.P. Barker from the south-western Cape. South Africa, is formally described. Descriptions of the morphology and leaf anatomy, in transectional and surface view, as observed under the light- and scanning electron microscope are given. Comparisons between this taxon and other southern African arundinoid species are made on the basis of morphological and anatomical observations. While the morphology of M setacea is in keeping with the generic limits of Merxmuellera Conert. the leaf blade anatomy appears to be intermediate between Merxmuellera, Pentameris Beauv. and  Pentaschistis (Nees) Spach.
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    A systematic study of the genus Pseudopentameris (Arundinoideae: Poaceae)
    (1995) Barker, N P
    The genus Pseudopentameris Conert is examined morphologically and anatomically. A phenetic study of the morphologica ly  variable species  P. macrantha indicates that two taxa should be recognised. One of these.  P. caespitosa N.P. Barker, is described as new. In addition, the study supports the inclusion of  Pentameris obtusifolia in  Pseudopentameris. The genus Pseudopentameris is re-delimited to accommodate the new taxa, and a key to species is provided. Details of the cytology, phylogeny and conservation status of taxa in the genus are also discussed.
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    External fruit morphology of southern African Arundineae (Arundinoideae: Poaceae)
    (1994) Barker, N P
    Fruits of a number of taxa of all indigenous southern African arundinoid genera were examined by means of SEM. Size, shape, compression, surface sculpturing, embryo anti hilum features were recorded and fruits of all genera are illustrated. Results are compared to existing descriptions. The genera are placed in five informal groups according to similarities noted in the fruits.
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    Phylogenetic relationships of the African species of the genus Merxmuellera Conert (Poaceae: Danthonioideae)
    (2001) Mafa, Paseka; Linder, Peter; Barker, N P
    This study expands on existing molecular (rpoC2 and ITS) and morphological data sets to further test the hypothesis of non-monophyly of Merxmuellera sensu lato. The results reveal that despite high levels of resolution, the morphological data yield poorly supported phylogenies due to high levels of homoplasy in the dataset.