Aim The aim of this paper is to determine the optimal methods for delimiting areas of endemism for Elegia L. (Restionaceae), an endemic genus of the Cape Floristic Region. We assess two methods of scoring the data (presence-absence in regular grids, or in irregular eco-geographical regions) and three methods for locating biogeographical centres or areas of endemism, and evaluate one method for locating biotic elements.Location The Cape Floristic Region (CFR), South Africa. MethodsThe distribution of all 48 species of Elegia was mapped as presenceabsence data on a quarter-degree grid and on broad habitat units (ecogeographical areas). Three methods to delimit areas of endemism were applied: parsimony analysis of endemism (PAE), phenetic cluster analysis, and NDM ('endemism'). In addition, we used presence-absence clustering ('Prabclus') to delimit biotic elements. The performances of these methods in elucidating the geographical patterns in Elegia were compared, for both types of input data, by evaluating their efficacy in maximizing the proportion of endemics and the number of areas of endemism.Results Eco-geographical areas perform better than quarter-degree grids. The eco-geographical areas are potentially more likely to track the distribution of species. The phenetic approach performed best in terms of its ability to delimit areas of endemism in the study area. The species richness and the richness of range-restricted species are each highest in the south-western part of the CFR, decreasing to the north and east. The phytogeographical centres identified in the present study are the northern mountains, the southern mountains (inclusive of the Riviersonderend Mountains and the Cape Peninsula), the Langeberg range, the south coast, the Cape flats, and the west coast.Main conclusions This study demonstrates that (1) eco-geographical areas should be preferred over a grid overlay in the study of biogeographical patterns, (2) phenetic clustering is the most suitable analytical method for finding areas of endemism, and (3) delimiting biotic elements does not contribute to an understanding of the biogeographical pattern in Elegia. The areas of endemism in Elegia are largely similar to those described in other studies, but there are many detailed differences.

The Podostemaceae (eudicots, Malpighiales) are adapted to rivers that exhibit distinct high-low water seasonality, mainly in the tropics. They attach to submerged rocks with ribbonlike or crustose green roots that cover the substrate like a carpet. Pronounced root dorsiventrality resulted in disklike crusts lacking root caps. African Podostemoideae show a bewildering array of forms not known from other flowering plants, such as (i) foliage leaves having a basis with two sheaths (e.g., Ledermanniella linearifolia), (ii) modular shoot construction with repeated stem cups (Ledermanniella ledermannii), (iii) endogenous origin of flowers along stems (Dicraeanthus africanus), and (iv) epiphyllous flowers (Ledermanniella letouzeyi). Important morphological transformations specific to African podostemoids include a shift from erect to inverted flowers in the spathella and unilocular ovaries arising via septum loss. New matK sequence data and new morphological data for eight African Podostemaceae species of the genera Dicraeanthus, Djinga, and Ledermanniella are combined with previously published sequences representing all major groups to test the placement of the African taxa in the family. All podostemoids studied from continental Africa form a clade that is sister to the Madagascan genera Endocaulos and Thelethylax. The sister of this African-Madagascan lineage is the clade comprising all Asian podostemoids and the American genus Podostemum, whereas all other New World podostemoids and the subfamily Tristichoideae are more basal.

Hardy, C R; Moline, P ; Linder, H P Hardy, C R; Moline, P; Linder, H P (2008 Difficulties with obtaining complete species-level phylogenies include (1) the accurate identification and sampling of species, (2) obtaining a complete species sampling, and (3) resolving relationships among closely related species.We addressed these in a study of 317 species and subspecies of the African Restionaceae. Accurate species identification and collection in the field was facilitated by a morphology-based interactive key to all species. Despite intensive fieldwork, however, material for DNA extraction could not be obtained for 20 of the 292 species of the focal Restio subclade. Furthermore, the 6831 aligned nucleotides and 1685 parsimonyinformative sequence characters were insufficient to resolve relationships fully within the clade. A simulation indicated that an additional 5000-7000 bases may have been needed to achieve supported resolution in the neighborhood of 95%-100%. Instead of further sequencing, we investigated the phylogenetic utility of the large set of characters contained within the interactive key data set, exploiting recent advances in parsimony and Bayesian programs that allow multistate and supermultistate (including continuous for parsimony) morphological characters. On doing so, parsimony resolution increased 17% to nearly 100%, and overall support increased in both parsimony (bootstrap) and Bayesian (posterior probability) frameworks. Taxa for which DNA data were lacking could be placed in fully resolved positions. Experiments using the parsimony ratchet indicated that placement of these morphology-only taxa may have been completely accurate 30% of the time, to within three nodes of accuracy 60% of time, and accurate to genus 96% of the time. Accurate placement of morphology-only taxa through Bayesian analysis may require extensive effort devoted toward exploring tree and parameter space. We conclude that the increasingly available large morphological data sets associated with interactive keys or informatics initiatives represent convenient yet potentially powerful tools in overcoming many of the commonly encountered obstacles in molecular-based species-level phylogenetics. Difficulties with obtaining complete species-level phylogenies include (1) the accurate identification and sampling of species, (2) obtaining a complete species sampling, and (3) resolving relationships among closely related species. We addressed these in a study of 317 species and subspecies of the African Restionaceae. Accurate species identification and collection in the field was facilitated by a morphology-based interactive key to all species. Despite intensive fieldwork, however, material for DNA extraction could not be obtained for 20 of the 292 species of the focal Restio subclade. Furthermore, the 6831 aligned nucleotides and 1685 parsimonyinformative sequence characters were insufficient to resolve relationships fully within the clade. A simulation indicated that an additional 5000-7000 bases may have been needed to achieve s...