Xylopia

Abstract: We recognize 30 species of the pantropical genus Xylopia L. from Madagascar and an additional three species from the Mascarene Islands. Of the six sections of the genus, three are represented in the region: sect. Xylopia, sect. Verdcourtia, and sect. Stenoxylopia. All species are endemic, and many are microendemics of conservation concern. The greatest species richness occurs in humid forests below 1000 m. Taxonomic review supports the hypothesis that the genus dispersed to Madagascar from continental Africa five times. Ten new species are described: Xylopia anomala D.M.Johnson & N.A.Murray, sp. nov., X. australis D.M.Johnson & N.A.Murray, sp. nov., X. carinata D.M.Johnson & N.A.Murray, sp. nov., X. galokothamna D.M.Johnson & N.A.Murray, sp. nov., X. lokobensis D.M.Johnson & N.A.Murray, sp. nov., X. longirostra D.M.Johnson & N.A.Murray, sp. nov., X. marojejyana D.M.Johnson & N.A.Murray, sp. nov., X. ravelonarivoi D.M.Johnson & N.A.Murray, sp. nov., X. retusa D.M.Johnson & N.A.Murray, sp. nov., and X. sclerophylla D.M.Johnson & N.A.Murray, sp. nov. An identification key, technical descriptions, illustrations, and distribution maps are provided.

Abstract: Dasyspora gregaria, the single species of the allegedly monotypic rust genus Dasyspora (Basidiomycota, Pucciniales), was investigated by light microscopy and DNA sequencing (ITS1-5.8S-ITS2 region, partial LSU and SSU of the nuclear rDNA, mt cytochrome oxidase subunit 3). Both methods indicated that D. gregaria is not a single species but can be split in 11 distinct taxa, each of which appear confined to a single Xylopia species (Annonaceae) host. Herein nine of these are described as new. Both the phylogenetic analyses and morphology show that the species are grouped into two main clades designated Dasyspora gregaria and D. winteri. The first comprises D. gregaria, the type species of the genus, which is restricted to X. cayennensis, two new species on X. aromatica, D. segregaria from northern South America and D. echinata from Brazil. The second clade is formed by D. winteri, recombined from Puccinia winteri on X. sericea, and the new species D. amazonica on X. amazonica, D. emarginatae on X. emarginata, D. frutescentis on X. frutescens, D. ferrugineae on X. frutescens var. ferruginea, D. guianensis on X. benthamii, D. mesoamericana on X. frutescens, and D. nitidae on X. nitida. Dasyspora frutescentis and D. mesoamericana were not clearly distinguishable by their morphology and host associations but differed from another in their sequences and geographic distributions. They are considered cryptic species. An identification key and the distributions are given for all recognized species. Along with molecular data we discuss the systematic position of Dasyspora in the Pucciniales.

Abstract: Summary The in vitro antiplasmodial activities of 14 plant species traditionally used in Central America for the treatment of malaria or fever were evaluated. Lipophilic extracts of Piper hispidum, Siparuna andina, S. pauciflora, S. tonduziana, and Xylopia cf. frutescens, proved to be active against both a chloroquine-sensitive and a resistant strain of Plasmodium falciparum. IC50 values ranged between 3.0 μg/ml and 21.9 μg/ml; however, moderate cytotoxicity of active extracts was observed. Bioactivity-guided fractionation of Piper hispidum yielded 2′,4,6′-trihydroxy-4′-methoxydihydrochalcone (asebogenin) as an active compound.

Abstract: Many species among the Tropical Annonaceae family are odorous; this property is due to the presence of essential oils which are mainly composed of mono- and sesquiterpene compounds The aim of this work is to give an overview of all published studies on the chemical composition of essential oils of various plant parts taken from numerous species belonging to different genera of Annonaceae In the Annonaceae, the main compounds are usually monoterpene hydrocarbons in fruit and seed oils, sesquiterpene hydrocarbons in leaf oils, and oxygenated sesquiterpenes in bark and root oils Most constituents identified are common, such as α-pinene, limonene, β-pinene, β-caryophyllene, p-cymene and caryophyllene oxide Other components seem to be more specific to a particular Annonaceae genus