Three new species of melastomataceae from the southeastern Atlantic Forest of Brazil

Three species are described here that occur in montane and high-montane forests in Southeastern Brazil.Miconia shepherdii belongs to sectionGlossocentrum and occurs on the Serra da Mantiqueira, on the border between the states of São Paulo, Minas Gerais, and Rio de Janeiro.Miconia kollmannii belongs to sectionHypoxanthus (formerChaenanthera) and occurs in the state of Espírito Santo.Ossaea suprabasalis was also collected in the state of Espírito Santo.     

Three new mesoamerican species of Miconia (Melastomataceae)

Miconia centrosperma andM. santaritensis from Panama, andM. stevensiana from Honduras, Nicaragua and Costa Rica, are described, illustrated, and compared with their presumed relatives.     

New taxa and combinations in Malvastrum A. Gray (Malvaceae: Malveae)

The genusMalvastrum A. Gray is interpreted to include 22 taxa in 14 species. Seven taxa are here described as new, namely:M. americanum var.stellatum,M. tomentosum subsp.pautense,M. bicuspidatum subsp.campanulatum,M. bicuspidatum subsp.oaxacanum, M. bicuspidatum subsp.tumidum var.tumidum, M. bicuspidatum subsp.tumidum var.glabrum, andM. coromandelianum subsp.fryxellii. In addition, two new combinations are proposed, namely:M. tomentosum andM. coromandelianum subsp.capitato-spicatum.     

Notes on melastomataceae of the guianas

New species of Melastomataceae from the Guianas are described in the genera Adelobotrys (Adelobotrys ayangannensis) and Clidemia (Clidemia ayangannensis, C. granvillei). Davya crassiramis Naudin is transferred as Meriania crassiramis, Tschudya pulverulenta DC. is given the new name Miconia aliquantula, and Henriettella venosa Gleason is transferred as Clidemia venosa.     

New and reconsidered species of tropical American Melastomataceae

Two species of berry-fruited Melastomataceae are described as new: Blakea unguiculata from the Caribbean lowlands of Panama, and Miconia mcphersonii from the Caribbean lowlands of Panama and lowland forests on the western slope of the Cordillera Occidental of Colombia. Discussions, distributional data, diagnostic illustrations, and a conservation assessment are provided for each of the new species. Meriania hoyosii, comb. nov. and M. compressicaulis , nom. nov. are proposed to effect the transfer of two species of Adelobotrys (A. hoyosii and A. panamensis respectively) to the genus Meriania. A revised key to the Mesoamerican species of Meriania is also provided.     

Miconia galeiformis and Miconia neei (Miconieae: Melastomataceae), two new species from Bolivia

Two new species of Miconia from Bolivia are described: Miconia galeiformis and Miconia neei. Both species occur in Andean montane forests. Miconia galeiformis (sect. Chaenopleura) is distinctive within Miconia due to the presence of setose stems, petioles and abaxial leaf surface, and a large, globose stigma. Miconia neei bears unisexual flowers, and can be distinguished from similar species of Miconia sect. Cremanium in Bolivia based on the furfuraceous stems and young nodes, in addition to serrulate leaf margins. The documentation of dioecy in Miconia neei and the occasional occurrence of unisexual flowers in Miconia galeiformis adds to our burgeoning understanding of complex breeding systems within Miconia.     

Toward a census of genus Mimosa (Mimosaceae) in the Americas: a new species from Mexico (Baja California Sur) and two from planaltine Brazil (Goiás, Minas Gerais)

Three new species of Mimosa are described: M. (sect. Batocaulon) epitropica Barneby & León de la Luz from Mexico (Baja California Sur); and two from planaltine Brazil, M. (sect. Habbasia) bispiculata Barneby and M. (sect. Mimosa) demissa Barneby. The affinity of each is discussed, and all are illustrated.     

Mycopteris,a new neotropical genus of grammitid ferns (Polypodiaceae)

Mycopteris, a new genus of grammitid ferns, is described and combinations are made for the species that belong to it. Mycopteris is diagnosed by castaneous rhizome scales with turgid cells, usually pectinate laminae, blackish petioles and rachises, blackish pinna costae and veins, reddish setae, cretaceous hydathodes, glabrous sporangia, and the presence of Acrospermum ascomes. It is entirely neotropical, ranging from Mexico east into the West Indies and south to Bolivia. Mycopteris is one of two genera of grammitid ferns that are consistently associated with Acrospermum, an epibiotic ascomycete that produces black clavate fruiting bodies. Seventeen species of Mycopteris are recognized here, including one new species (M. longipilosa) and one elevated from the rank of variety to species (M. costaricensis). The following additional combinations are made here: M. alsopteris, M. amphidasyon, M. attenuatissima, M. cretata, M. grata, M. leucolepis, M. leucostica, M. longicaulis, M. pirrensis, M. praeceps, M. semihirsuta, M. steyermarkii, M. subtilis, M. taxifolia, and M. zeledoniana. Lectotypes are chosen for Ctenopteris leucosticta, Polypodium amphidasyon, and Polypodium pectinatum var. hispidum. For each accepted species, full synonymy and geographical range are provided. Taxonomic discussion is provided for species not widely recognized in previous treatments.     

A conspectus of Mexican and Central American Picramnia (Simaroubaceae)

A complete checklist with synonymy and notes is provided for the Mexican and Central American species ofPicramnia. A key to all taxa of the region is included. Four new taxa (Picramnia guerrerensis, P. hirsuta, P. deflexa, andP. antidesma subsp.nicaraguensis) are described and illustrated, and a new combination (Picramnia antidesma subsp.fessonia) is made.     

Characterization of the sugar-O-methyltransferase LobS1 in lobophorin biosynthesis

Lobophorins A (1) and B (2) belong to a large group of spirotetronate natural products with potent antibacterial and antitumor activities. The cloning of the lobophorin biosynthesis gene cluster from the deep-sea-derived Streptomyces sp. SCSIO 01127 identified a sugar-O-methyltransferase-encoding gene lobS1. The lobS1 inactivation mutant accumulated two new lobophorin analogs 3 and 4, different from 1 and 2 by lacking the 4-methyl group at the terminal l-digitoxose, respectively. Biochemical experiments verified that LobS1 was a SAM-dependent sugar-O-methyltransferase that required divalent metal ions for better activity. Antibacterial assays revealed compounds 3 and 4 were generally less potent than compounds 1 and 2. These findings suggest that the methylation on the terminal digitoxose by LobS1 tailors lobophorin biosynthesis and highlights the importance of this methylation for antibacterial potence.     

New combinations in Hawaiian Chamaesyce (Euphorbiaceae)

Chamaesyce is accepted at the genus level for the Hawaiian taxa. The following new combinations are made:C. celastroides var.laehiensis, C. celastroides var.tomentella, C. rockii var.grandifolia, C. skottsbergii var.vaccinioides, andC. sparsiflora.     

Arceuthobium (Viscaceae) in Mexico and Guatemala: Additions and range extensions

Three new dwarf mistletoes are described:Arceuthobium globosum subsp.grandicaule (Mexico and Guatemala),A. aureum subsp.aureum (Guatemala) andA. aureum subsp.petersonii (Chiapas, Mexico).Arceuthobium guatemalense is recorded for the first time in Mexico. Significant range extensions are recorded forA. abietisreligiosae, A. divaricatum,A. gillii subsp.nigrum, andA. rubrum. New hosts are reported for several taxa. Nineteen members of the genus are presently known from Mexico, and three (possibly four) from Guatemala. Chromosome counts are reported for the first time for 3 taxa.     

New species of Pectis (Asteraceae) from the West Indies,Mexico, and South America

Four new species ofPectis are described:P. ericifolia from Barbuda,P. luckoviae from west-central Mexico,P. arida from Ecuador and Peru, andP. cajamarcana from Peru. Chromosome counts forP. ericifolia (n=48) andP. luckoviae (n=12) are presented. Relationships of the newly described taxa are discussed.