A revision of the genus Oxytheca Nutt. (Polygonaceae)

The genusOxytheca of western North America and temperate South America consists of seven species which are keyed, described, discussed, illustrated, and mapped. They are divided among sect.Oxytheca, sect.Acanthoscyphus stat. & comb. nov., and sect.Neoxytheca sect. nov.Oxytheca dendroidea subsp.chilensis is given as a new combination, whileO. parishii var.cienegensis andO. parishii var.goodmaniana are described as new. The history and relationships of the genus are discussed. It is retained as distinct fromEriogonum and is thought to have arisen from the larger genus nearE. spergulinum, E. parishii, andE. apiculatum in subgenusGanysma. Cytological data indicatedn= 20.     

Novelties in Serjania (Sapindaceae)

Three new species ofSerjania (S. magnistipulata andS. mori from Bahía, Brazil andS. schunkei from Perú) are described, discussed, and illustrated.     

Dragma Hippomanicum V: Two new Astragali from Intermountain United States

Astragalus (sect.Argophylli subsect.Pseudargophylli)holmgreniorum, from the Virgin valley along the Utah-Arizona border, and A. (sect.Reventi-Arrecti subsect. Orcuttiani)ackermanii, from S Nevada, are described, figured and discussed.     

Three new Brazilian species of chamaecrista moench (Leguminosae: Caesalpinioideae)

Chamaecrista (sect.Apoucouita) aspidiifolia Irwin & Barneby from Bahia,Ch. (sect.Absus) glischrodes Irwin & Barneby from Minas Gerais andCh. (sect.Absus)didyma Irwin & Barneby from Brazilian Amazonia are described, figured, and discussed in terms of affinity. Several incidental new combinations inChamaecrista are proposed.     

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.     

Two new mimosaceous trees from the American Tropics

Piptadenia (sect.Pityrocarpa)leucoxylon is described from the lower Orinoco basin in Venezuela, andPithecellobium (sect.Samanea)foederale from Distrito Federal, Brazil. Figures, diagnoses, and discussion of kinship are presented for each.     

Two new species of Serjania (Sapindaceae) from Brazil

Two new Brazilian species,Serjania fluminensis andS. unidentata, are described, illustrated, and discussed.     

Three new species of penstemon (Scrophulariaceae) from the Intermountain Region

Penstemon goodrichii of sect.Cristati andP. navajoa andP. moriahensis of sect.Glabri are described, illustrated and mapped. Their relationships to kindred species are discussed.     

Two new species of Dioscorea (Dioscoreaceae) from Peru

Two new species ofDioscorea,D. gentryi (subgen.Helmia sect.Monadelpha) andD. andromedusae (subgen.Helmia sect.Centrostemon) from Peru, are described and illustrated.     

Novae Gesneriaceae neotropicarum VI: five new Gesneriaceae from northwestern South America

Columnea chrysotricha, C. cuspidata (bothColumnea sect.Collandra), andGasteranthus recurvatus are described from Colombia;C. sulcata (Columnea sect.Collandra) from Ecuador and Colombia; andDrymonia anisophylla from the Amazonian lowland rain forests of Brazil, Colombia, Ecuador, and Peru.     

Chusquea sect. Swallenochloa (Poaceae: Bambusoideae) and allies in Brazil

The 13 high altitude/latitude, dwarf species ofChusquea in Brazil are described, illustrated, and mapped, and their morphology, habitats, distributions, and taxonomic affinities are discussed. Two keys to species are provided, one based solely on vegetative characters, and the other on vegetative and flowering characters.Chusquea erecta, C. nutans, C. riosaltensis,C. windischii, C. caparaoensis, andC. nudiramea are described as new, andC. microphylla is elevated to specific status. Two subspecies are recognized within the variableC. mimosa: C. mimosa subsp.australis and subsp.mimosa. Seven species are formally classified withinChusquea sect.Swallenochloa; the remaining six species are classified into two informal categories, theNudiramea andHeterophylla groups. A list of all the species currently included withinChusquea sect.Swallenochloa is provided.     

Two new Brazilian species of Chamaecrista Moench (Leguminosae: Caesalpinioideae)

Chamaecrista (sect.Apoucouita) onusta Irwin & Barneby from coastal Bahia andCh. (sect.Absus) hatschbachii Irwin & Barneby from north-central Minas Gerais are described, figured and systematically characterized. Four new combinations inChamaecrista incidental to the discussion are proposed.     

Dragma Hippomanicum VII: A new alpine astragalus (Leguminosae) from western Wyoming

Astragalus (sect.Minerales) shultziorum, related toA. molybdenus Barneby which is endemic to the tundra zone of the Colorado Rocky Mountains, is described from the crest of the Salt River Range in western Wyoming, illustrated and discussed.     

Three new species of Mimosa sect. Mimosa (Leguminosae,Mimosoideae) from the campos rupestres of Minas Gerais,Brazil

Three new species of Mimosa sect. Mimosa ser. Mimosa subser. Polycephalae (Leguminosae, Mimosoideae) are described and illustrated. Mimosa canastrensis, Mimosa chrysothrix, and Mimosa decumbens are all from the campos rupestres of Minas Gerais, Brazil. Discussions about the distributions, habitat, and phenology of the species are provided, in addition to comparisons with similar taxa.     

Two new taxa in dalea (Fabaceae: Amorpheae) from southern Mexico and Northern Chile

Dalea acracarpica, from Chiapas, Mexico is described, illustrated, and referred to sect. Parosela ser. Lasiostomae: the var. chilensis is a yellow-flowered Chilean counterpart of purple Peruvian D. pennellii var. pennellii.     

Begonia lyman-smithii (Begoniaceae), a new species from Oaxaca,Mexico

Begonia (sect.Gireoudia)lyman-smithii is described and illustrated, and its relationships are discussed.     

Evidence for several genomes in Helianthus

Forty taxa belonging to 36 species and four unclassified accessions of Helianthus were studied using RAPD technology. Single ten-mer primers were screened for those amplifying fragments common to several species. We found that when several species shared a common fragment, they belong to the same section of the genus. Moreover, we also found that some fragments are common to all species of the Helianthus. Most of the fragments were found to be of the same size in these species and to share the homology indicated by molecular hybridization. Out of 118 retained fragments, 33 were common to all Helianthus species, 56 were unique to perennial species of sects. Atrorubentes and Ciliares, 24 were unique to sect. Atrorubentes, 29 were unique to sect. Helianthus, whereas 0 were unique to sect. Ciliares. Each set of common or specific fragments was assumed to belong to a genome: (1)?the C genome carrying the fragments common to all species of the three sections, (2)?the H genome unique to sect. Helianthus, (3)?the P genome common to perennial species (sects. Atrorubentes and Ciliares), and (4)?the A genome unique to sect. Atrorubentes. The genomic structure was therefore HC for sect. Helianthus, CPA for sect. Atrorubentes, and CP? for sect. Ciliares. Molecular hybridizations with amplification products revealed homologies between Helianthus genomes and several other genera in the Helianthinae sub-tribe. The simple method used to characterize these fragments led to powerful tools for recognizing genomes which reconcile the section organization of the genus and the degree of difficulty in crossing perennial and annual forms.     

Revision of Plerandra (Araliaceae). I. A synopsis of the genus with an expanded circumscription and a new infrageneric classification

Phylogenetic studies have demonstrated that Schefflera, the largest genus of Araliaceae, is grossly polyphyletic, comprising five distinct clades within the family. In an effort to establish monophyletic genera among the elements that currently comprise Schefflera, the genus Plerandra is expanded to encompass all of the members of one of these clades. In this synoptical revision, a new infrageneric classification is presented (along with a key) in which six subgenera are recognized. Four of these subgenera are newly described (Plerandra subgenera Canacoschefflera, Costatae, Gabriellarum, and Veilloniorum) and a fifth represents a new combination (Plerandra subg. Dizygotheca). A total of 33 species (one with two subspecies) are accepted, one of which is newly described (P. veilloniorum), and 22 new combinations are made (P. actinostigma, P. baillonii, P. cabalionii, P. costata, P. crassipes, P. elegantissima, P. elongata, P. emiliana, P. gabriellae, P. leptophylla, P. nono, P. osyana, P. osyana subsp. toto, P. pachyphylla, P. pancheri, P. plerandroides, P. polydactylis, P. reginae, P. seemanniana, P. tannae, P. vanuatua, P. veitchii). Neotypes are provided for six accepted names and one heterotypic synonym, and lectotypes are designated for 13 accepted names and 16 heterotypic synonyms. For each accepted species, full synonymy is provided along with geographic range and notes.