470 research outputs found

    Bouteloua Chihuahuana (Gramineae), A New Nomenclatural Combination

    Get PDF
    A revision of the Euphorbia dioscoreoides complex (subgenus Agaloma) is provided. Euphorbia dioscoreoides ssp. attenuata and E. eglandulosa, both from Mexico, are proposed as new; E. digitata is reduced to synonymy under E. subpeltata. Representative specimens are cited, and distributional and ecological data are provided

    An expanded circumscription of Bouteloua (Gramineae: Choridoideae): new combinations and names

    Get PDF
    Cladistic analysis of nuclear ribosomal and chloroplast DNA sequences has revealed that the New World grass genus Bouteloua (Chloridoideae) is not monophyletic. Indeed, some species of Bouteloua are more closely related to species in other genera than to congeners. The problem was dealt with by expanding the circumscription of Bouteloua to include species formerly positioned in the satellite genera Buchloe (1 species), Buchlomimus/em\u3e (1), Cathestecum/em\u3e (4), Cyclostachya/em\u3e (1), Griffithsochloa (1), Opizia (2), Pentarrhaphis (3), Pringleochloa (1), and Soderstromia(1). Thirteen new combinations and names were necessary. As here circumscribed, Bouteloua is monophyletic and comprises 57 species

    Mary H. Gibbon: teamwork of the heart.

    Get PDF
    Mary Maly Hopkinson Gibbon was born on September 25, 1903, to an affluent New England family who encouraged her to embrace her intelligence and to follow that by which she was intrigued. In doing this, Maly pursued work in scientific research, where she ultimately met her first husband, Dr. John ā€˜ā€˜Jackā€™ā€™ H. Gibbon. Jack and Maly were partners in every sense of the word. Their collaboration, both within and beyond the walls of the research laboratory, made it possible for the Gibbon dream of the heartā€“lung machine to be realized

    Nomenclatural Changes for Some Grasses in California. II.

    Get PDF
    Two additional nomenclatural changes are required for Poaceae treatments that will appear in the second edition of The Jepson Manual: Higher Plants of California. They are Elymus x gouldii and Festuca temulenta. The former corrects a violation of the rule in the International Code of Botanical Nomenclature involving the naming of hybrids, and the latter involves a widely occurring non-native grass in California traditionally assigned to Lolium

    The Chromosome Number of Schaffnerella Gracilis (Gramineae, Chloridoideae)

    Get PDF
    The first ever chromosome report for the monotypic genus Schaffnerella (Grarnineae, Chloridoideae) is 2n = 20 (10 II) from pollen parent cells at diakinesis, which indicates diploidy and a base number of 10. The close relative Lycurus likewise has x = 10, but is tetraploid (2n = 4x = 40)

    Classification and Biogeography of New World Grasses: Chloridoideae

    Get PDF
    Subfamily Chloridoideae (Poaceae) in the New World includes 72 genera (61 native, 11 introduced), 678 species (607 native), and, including intraspeciļ¬c taxa, 817 total taxa. The ļ¬ve largest genera are Muhlenbergia (147 species), Eragrostis (111), Sporobolus (76), Bouteloua (57), and Chloris (35). Three tribes are recognized in this study: Cynodonteae, Eragrostideae, and Zoysieae, with ten, three, and two subtribes, respectively. Cynodonteae, the largest tribe, comprise 58 genera and 451 species (67% of all New World chloridoids), including 25 genera (98 species, 22% of all New World Cynodonteae) with unknown afļ¬nities (incertae sedis). In Mexico, the USA, and Canada there are 477 native and introduced chloridoid species (70% of all New World species), whereas in Central America (including the Caribbean) and South America there are 196 and 304 species, respectively. Mexico is the center of diversity with 343 species (51%). There appear to be ļ¬ve biogeographical patterns exhibited by New World chloridoid species: (1) North America, centered in northern Mexico and the southwestern USA, (2) southern South America, centered in northern Argentina, Paraguay, Uruguay, and southern Brazil, (3) northwestern South America, centered in Ecuador and Peru, (4) amphitropical disjuncts, occurring in North America and southern South America, and (5) widespread species, occurring in North America, Central America, and South America. Subtribes Boutelouinae (Bouteloua) and Muhlenbergiinae are predominantly North American, whereas Eragrostidinae (Eragrostis) and Chloridinae are better represented in the southern South American center. Two subtribes of Cynodonteae, Gouiniinae and Hilariinae, are described as new, and two others, Orcuttiinae and Traginae, are newly treated at that rank

    Nomenclatural Changes for Some Grasses in California and the Muhlenbergia Clade (Poaceae)

    Get PDF
    New combinations and names are here validated for ten grass (Poaceae) taxa in California for the forthcoming revision of The Jepson Manual. In addition, guided by recent molecular phylogenetic studies, ten non-California grass species are here transferred to Muhlenbergia (Chloridoideae: Cynodonteae) to achieve monophyly of the genus. Lolium, long known to be phylogenetically nested within Festuca, is here subsumed into Festuca, and the circumscription of Stipa is expanded to include all Stipeae (native and non-native) in California. In Stipeae, most currently recognized genera are not monophyletic. Attaining monophyly while bearing in mind identification for persons not expert in Stipeae were the guiding principles in expanding the circumscription of Stipa. Newly recognized are: Elymus elymoides var. californicus, E. elymoides var. hordeoides, Festuca perennis, Hilaria subgen. Pleuraphis, Muhlenbergia brevigluma, M. diandra, M. imperfecta, M. multiflora, M. paniculata, M. phleoides, M. plumiseta, M. spatha, M. tricholepis, M. uniseta, Schismus barbatus var. arabicus, Stipa chaetophora, S. divaricata, S. exigua, S. mauritanica, and S. purpurata

    Precision metering of microliter volumes of biological fluids in micro-gravity

    Get PDF
    Concepts were demonstrated and investigated for transferring accurately known and reproducible microliter volumes of biological fluids from sample container onto dry chemistry slides in microgravity environment. Specific liquid transfer tip designs were compared. Information was obtained for design of a liquid sample handling system to enable clinical chemical analysis in microgravity. Disposable pipet tips and pipet devices that were designed to transfer microliter volumes of biological fluid from a (test tube) sample container in 1-G environment were used during microgravity periods of parabolic trajectories of the KC-135 aircraft. The transfer process was recorded using charge coupled device camera and video cassette equipment. Metering behavior of water, a synthetic aqueous protein solution, and anticoagulated human blood was compared. Transfer of these liquids to 2 substrate materials representative of rapidly wettable and slowly wettable dry chemistry slide surface was compared

    Kalinia, a New North American Genus for a Species Long Misplaced in Eragrostis (Poaceae, Chloridoideae)

    Get PDF
    Eragrostis obtusiflora (Poaceae, Chloridoideae), a species distributed from the southwestern United States to central Mexico, has long been recognized for exhibiting morphological and anatomical features atypical of Eragrostis. Phylogenetic analyses of nuclear internal transcribed spacer sequences and plastid sequences demonstrate that E. obtusiflora should be excluded from Eragrostis (Eragrostideae) and instead be placed in Cynodonteae, although its position within this tribe was unresolved. Additional data, including anatomical and micromorphological characters, suggest a close relationship with Distichlis. However, differences in spikelet and rhizome characters prevent its inclusion in Distichlis. Therefore, the species is transferred to a newly described genus, Kalinia, as K. obtusiflora

    Phylogenetics of Andropogoneae (Poaceae: Panicoideae) Based on Nuclear Ribosomal Internal Transcribed Spacer and Chloroplast trnLā€“F Sequences

    Get PDF
    Phylogenetic relationships among 85 species representing 35 genera in the grass tribe Andropogoneae were estimated from maximum parsimony and Bayesian analyses of nuclear ITS and chloroplast trnLā€“F DNA sequences. Ten of the 11 subtribes recognized by Clayton and Renvoize (1986) were sampled. Independent analyses of ITS and trnLā€“F yielded mostly congruent, though not well resolved, topologies. Arundinella is sister to Andropogoneae in the trnLā€“F phylogeny and is nested within the tribe in the ITS and combined data trees. Tristachya is sister to Andropogoneae + Arundinella in the ITS phylogeny. Four clades are common to the ITS and trnLā€“F phylogenies and the trees from the combined data set. Clade A consists of Andropogon, Diectomis, Hyparrhenia, Hyperthelia, and Schizachyrium. Within this clade, Andropogon distachyos, Hyparrhenia, and Hyperthelia form clade C. Clade B consists of Bothriochloa, Capillipedium, and Dichanthium, and clade D includes Chrysopogon and Vetiveria. Analysis of the combined data resulted in an unsupported larger clade comprising clades A and B plus Cymbopogon, and a sister clade of Heteropogon, Iseilema, and Themeda. This larger clade is similar to the core Andropogoneae clade previously reported (Spangler et al. 1999; Mathews et al. 2002). Based on our sample, which represents 41% of the tribeā€™s genera, most of Clayton and Renvoizeā€™s (1986) subtribes are not monophyletic
    • ā€¦
    corecore