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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Royal Botanic Gardens, Kew and Springer are collaborating with JSTOR to digitize, preserve and extend access to Kew Bulletin. Summary. Circumscription of Flacourtiaceae was investigated with a phylogenetic analysis of plastid rbcL DNA sequences, and the family was found to be composed of two clades that are more closely related to other families in Malpighiales than to each other. In one of these, that containing the type genus Flacourtia, Salicaceae are embedded, whereas the other clade includes the members of the peculiar and poorly known South African Achariaceae. The latter family name is conserved against all listed synonyms. Thus we propose the recognition of two families: i) Salicaceae sensu lato, including tribes Banareae, Bembicieae, Scolopieae, Samydeae (syn. Casearieae), Homalieae, Flacourtieae, Prockieae and Saliceae, as well as Abatieae (by some authors of Passifloraceae) and Scyphostegieae (Scyphostegia of the monogeneric Scyphostegiaceae); and ii) Achariaceae sensu lato, including tribes Pangieae, Lindackerieae, Erythrospermeae and Acharieae (Acharia, Ceratiosicyos and Guthriea of Achariaceae). Several genera considered by many previous authors to be members of Flacourtiaceae are excluded from Malpighiales: Berberidopsis and Aphloia fall near the base of the higher eudicots. Several tribes require different names from those used in previous systems, and we include an appendix indicating a tentative revised tribal taxonomy for both Salicaceae and Achariaceae sensu lato. INTRODUCTIONFlacourtiaceae are a woody, pantropical family of 80 -95 genera (including 800 -1,000 species) that are frequently difficult to diagnose in the field because of their extremely heterogeneous floral morphology. For no other family of flowering plants has circumscription been so variable and controversial. Aside from these problems (concerning roughly 15 -20 of the genera or 20% of the family), circumscription of the remaining portion of Flacourtiaceae has remained more or less constant since 1925 (Gilg 1925, Hutchinson 1967, Lemke 1988, Sleumer 1954, 1980, Takhtajan 1997). The main areas of disagreement have concerned the inclusion of tribes Abatieae and Paropsieae (often referred to Passifloraceae) and Prockieae (frequently treated as members of Tiliaceae), and a number of genera referred to small unior bigeneric families, e.g., Aphloiaceae Takht. (Aphloia), Berberidopsidaceae (Veldk.) 141 142 KEW BULLETIN VOL. 57(1)Lemke's (1988) synopsis of Flacourtiaceae included 10 tribes, 79 genera and 880 species and provided revised familial and tribal descriptions based on macromorphology, palynology, phytochemistry and xylem anatomy. Lemke's aim was to improve on the earlier work of Hutchinson (1...

Phylogenetic relationships within Limonium (Plumbaginaceae) are evaluated using sequence data from three plastid regions (rbcL, the trnL intron, and the trnL-trnF intergenic spacer). Sixty-six species representing the major genera of Staticoideae, including representatives of all sections and genera formerly included in Limonium, have been analyzed using four species of Plumbaginoideae as an outgroup. Analyses of each separate and combined data set yield similar results. Afrolimon is embedded in Limonium and related to L. vulgare, the type of Limonium. Limonium is split into two major clades corresponding to subgenera, but otherwise the current infrageneric classification proved to be artificial. Some groups restricted to particular areas can be recognized, and their synapomorphies are discussed. The presence of an isolated taxon in the Canary Islands is used as a calibration point for age estimates of the major events in the genus, including migrations to the Southern Hemisphere, the Canary Islands, and Asia. The rapid radiation of Limonium in the Mediterranean basin appears to coincide with the desiccation of the Mediterranean Sea in the Messinian (late Miocene).

The monophyly and phylogenetic relationships of Plumbaginaceae (sensu Cronquist) were evaluated using parsimony analysis of nucleotide sequences of the plastid gene rbcL. Analysis of 42 taxa, including 18 species of Plumbaginaceae, placed this family as a strongly supported monophyletic group sister to Polygonaceae and in the same clade as Simmondsiaceae, Nepenthaceae, Droseraceae and Caryophyllales. Within Plumbaginaceae, two well supported groups are present, corresponding to subfamilies Plumbaginoideae and Staticoideae. These groups have been regarded as independent families by some authors, and anatomical, morphological and biochemical differences are well defined. The taxonomic status of each group is discussed.

BackgroundAdaptive radiation in Mediterranean plants is poorly understood. The white-flowered Cistus lineage consists of 12 species primarily distributed in Mediterranean habitats and is herein subject to analysis.Methodology/Principal FindingsWe conducted a “total evidence” analysis combining nuclear (ncpGS, ITS) and plastid (trnL-trnF, trnK-matK, trnS-trnG, rbcL) DNA sequences and using MP and BI to test the hypothesis of radiation as suggested by previous phylogenetic results. One of the five well-supported lineages of the Cistus-Halimium complex, the white-flowered Cistus lineage, comprises the higher number of species (12) and is monophyletic. Molecular dating estimates a Mid Pleistocene (1.04±0.25 Ma) diversification of the white-flowered lineage into two groups (C. clusii and C. salviifolius lineages), which display asymmetric characteristics: number of species (2 vs. 10), leaf morphologies (linear vs. linear to ovate), floral characteristics (small, three-sepalled vs. small to large, three- or five-sepalled flowers) and ecological attributes (low-land vs. low-land to mountain environments). A positive phenotype-environment correlation has been detected by historical reconstructions of morphological traits (leaf shape, leaf labdanum content and leaf pubescence). Ecological evidence indicates that modifications of leaf shape and size, coupled with differences in labdanum secretion and pubescence density, appear to be related to success of new species in different Mediterranean habitats.Conclusions/SignificanceThe observation that radiation in the Cistus salviifolius lineage has been accompanied by the emergence of divergent leaf traits (such as shape, pubescence and labdanum secretion) in different environments suggets that radiation in the group has been adaptive. Here we argued that the diverse ecological conditions of Mediterranean habitats played a key role in directing the evolution of alternative leaf strategies in this plant group. Key innovation of morphological characteristics is supported by our dated phylogeny, in which a Mediterranean climate establishment (2.8 Ma) predated the adaptive radiation of the white-flowered Cistus.

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