Fruits of Koelreuteria (Sapindaceae) from the Cenozoic throughout the northern hemisphere: their ecological, evolutionary, and biogeographic implications.

abstract：:Cladistic analyses of plastid DNA sequences rbcL and trnL-F are presented separately and combined for 48 genera of Amaryllidaceae and 29 genera of related asparagalean families. The combined analysis is the most highly resolved of the three and provides good support for the monophyly of Amaryllidaceae and indicates Ag...

journal_title：American journal of botany

authors： Meerow AW,Fay MF,Guy CL,Li QB,Zaman FQ,Chase MW

更新日期：1999-09-01 00:00:00

abstract：:We investigated patterns of fruit and seed production on inflorescences of a population of Pancratium maritimum in northwest Spain over a 2-yr period. Initial findings showed that the earliest opening flowers on an inflorescence are more likely to set fruit and produce more seeds than later opening flowers and that th...

journal_title：American journal of botany

authors： Medrano M,Guitián P,Guitián J

更新日期：2000-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Species formation is an intuitive endpoint of reproductive isolation, but circumscribing taxa that arise during speciation can be difficult because of gene flow, morphological continuity, hybridization or polyploidization, and low sequence variation among newly diverged lineages. Nonetheless, speci...

journal_title：American journal of botany

authors： Stoughton TR,Kriebel R,Jolles DD,O'Quinn RL

更新日期：2018-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Functional trait plasticity in resource capture traits has been suggested as an underlying mechanism promoting invasive species establishment and spread. Earlier studies on this mechanism treat invasiveness as a discrete characteristic (i.e., invasive vs. noninvasive) and do not consider the potent...

journal_title：American journal of botany

authors： Murphy JE,Burns JH,Fougère-Danezan M,Drenovsky RE

更新日期：2016-12-01 00:00:00

abstract：PREMISE OF THE STUDY:Factors shaping spatiotemporal patterns of associations in mutualistic systems are poorly understood. We used the lichen-forming fungi Peltigera and their cyanobacterial partners Nostoc to investigate the spatial structure of this symbiosis at an intrabiome scale and to identify potential factors s...

journal_title：American journal of botany

authors： Lu J,Magain N,Miadlikowska J,Coyle JR,Truong C,Lutzoni F

更新日期：2018-07-01 00:00:00

abstract：:• Premise of the study: Wild populations of domesticated species constitute a genetic reservoir and are fundamental to the evolutionary potential of species. Wild papaya (Carica papaya) is a rare, short-lived, gap-colonizing, dioecious tree that persists in the forest by continuous dispersal. Theoretically, these life...

journal_title：American journal of botany

authors： Chávez-Pesqueira M,Suárez-Montes P,Castillo G,Núñez-Farfán J

更新日期：2014-07-01 00:00:00

abstract：:Senna (Leguminosae) is a large, widespread genus that includes species with enantiostylous, asymmetric flowers and species with extrafloral nectaries. Clarification of phylogenetic relationships within Senna based on parsimony analyses of three chloroplast regions (rpS16, rpL16, and matK) provides new insights on the ...

journal_title：American journal of botany

authors： Marazzi B,Endress PK,Queiroz LP,Conti E

更新日期：2006-02-01 00:00:00

abstract：:Intensified ultraviolet-B radiation or UV-B (wavelengths between 280 and 320 nm) can delay flowering and diminish lifetime flower production in a few plants. Here we studied the effects of enhanced UV-B on floral traits crucial to pollination and pollinator reproduction. We observed simultaneous flowering responses of...

journal_title：American journal of botany

authors： Sampson BJ,Cane JH

更新日期：1999-01-01 00:00:00

abstract：:Wood, or secondary xylem, is composed mostly of three components-cellulose, hemicelluloses, and lignin. Yet this apparent simplicity is deceiving because the sophisticated arrangement of the components on various structural levels, ranging from intricate molecular architecture to defined cellular arrangements to tissu...

journal_title：American journal of botany

authors： Koehler L,Telewski FW

更新日期：2006-10-01 00:00:00

abstract：:Partial cambial mortality is a growth form that is characteristic of Pinus aristata trees. To better elucidate their cambial death pattern, tree size and aspect of cambial death data were gathered from three Pinus aristata forests in central Colorado, USA. Stripping frequency tended to be higher for larger diameter cl...

journal_title：American journal of botany

authors： Schauer AJ,Schoettle AW,Boyce RL

更新日期：2001-04-01 00:00:00

abstract：:In contrast to most angiosperms, in which fertilization occurs 1 or 2 days after pollination, in some plant orders, including the Fagales, fertilization is delayed from 4 days to more than 1 year, raising questions regarding why fertilization is delayed and where and how pollen tubes remain in the pistil during the de...

journal_title：American journal of botany

authors： Sogo A,Tobe H

更新日期：2006-12-01 00:00:00

abstract：:Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the typ...

journal_title：American journal of botany

authors： Lomelí-Sención JA,Sahagún-Godínez E

更新日期：2002-09-01 00:00:00

abstract：PREMISE:The cosmopolitan and ecologically important grass subfamily Aristidoideae comprises the widely distributed genus Aristida (250-290 species), Stipagrostis (50 species, with an African-Asian distribution), and Sartidia (five species, Africa and Madagascar). The subfamily includes species with C(3) (Sartidia and a...

journal_title：American journal of botany

authors： Cerros-Tlatilpa R,Columbus JT,Barker NP

更新日期：2011-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Virtually nothing is known about what actually happens during prolonged dormancy, the period during which significant proportions of geophyte populations do not sprout after seasonal dormancy but remain alive underground, to emerge again 1 or more years later. This study investigated the fate of pe...

journal_title：American journal of botany

authors： Gregg KB

更新日期：2011-02-01 00:00:00

abstract：PREMISE:Although hybridization has played an important role in the evolution of many plant species, phylogenetic reconstructions that include hybridizing lineages have been historically constrained by the available models and data. Restriction-site-associated DNA sequencing (RADseq) has been a popular sequencing techni...

journal_title：American journal of botany

authors： Blanco-Pastor JL,Bertrand YJK,Liberal IM,Wei Y,Brummer EC,Pfeil BE

更新日期：2019-09-01 00:00:00

abstract：PREMISE OF THE STUDY:A knowledge of pollen characters in early-diverging angiosperm lineages is essential for understanding pollen evolution and the role of pollen in angiosperm diversification. In this paper, we report and synthesize data on mature pollen and pollen ontogeny from all genera of Nymphaeales within a com...

journal_title：American journal of botany

authors： Taylor ML,Cooper RL,Schneider EL,Osborn JM

更新日期：2015-10-01 00:00:00

abstract：:The utility of regression and correspondence models for deducing climate from leaf physiognomy was evaluated by the comparative application of different predictive models to the same three leaf assemblages. Mean annual temperature (MAT), mean annual precipitation (MAP), and growing season precipitation (GSP) were esti...

journal_title：American journal of botany

authors： Wiemann MC,Manchester SR,Dilcher DL,Hinojosa LF,Wheeler EA

更新日期：1998-12-01 00:00:00

abstract：:We analyzed the effects of temporal variation in floral display size (number of flowers open at one time on a plant) on the rate of pollen removed and receipt of individual flowers for the sequential blooming plant Narthecium asiaticum (Liliaceae). Because of the acropetal blooming of this species, the display sizes w...

journal_title：American journal of botany

authors： Ishii HS,Sakai S

更新日期：2002-03-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:The growth limitation hypothesis (GLH) is the most accepted mechanistic explanation for treeline formation, although it is still uncertain whether it applies across taxa. The successful establishment of Pinus contorta--an exotic conifer species in the southern hemisphere--above the No...

journal_title：American journal of botany

authors： Fajardo A,Piper FI

更新日期：2014-05-01 00:00:00

abstract：:The American chestnut (Castanea dentata; Fagaceae) was a dominant canopy tree in the Appalachian Mountains of North America. Since the introduction of the chestnut blight fungus (Cryphonectria parasitica; Valsaceae) in America, the American chestnut has been reduced to a predominantly clonal, understory species. Our o...

journal_title：American journal of botany

authors： Stilwell KL,Wilbur HM,Werth CR,Taylor DR

更新日期：2003-02-01 00:00:00

abstract：:The phenotype of maize plants that are homozygous recessive for the nuclear gene iojap is commonly an "anemic," grainy green appearance accompanied by white leaf stripes, white leaf margins, and reduced growth. In plants in which the iojap effect is occurring (homozygous ij/ij), we find affected tissue varies in exten...

journal_title：American journal of botany

authors： Coe EH Jr,Thompson D,Walbot V

更新日期：1988-05-01 00:00:00

abstract：:Ontogenetic changes in architecture, carbohydrate reserves, and resource allocation can constrain the ability of plants to compensate for herbivore damage. To evaluate ontogenetic changes in compensation, saplings and reproductive individuals of the tropical tree Casearia nitida were subjected to three levels of defol...

journal_title：American journal of botany

authors： Boege K

更新日期：2005-10-01 00:00:00

abstract：:Long-distance transplantation of seed material as done in restoration programs has raised concerns about the risks associated with the introduction of maladapted genotypes that may hybridize with neighboring native conspecifics and decrease local population fitness (outbreeding depression). We studied the consequences...

journal_title：American journal of botany

authors： Crémieux L,Bischoff A,Müller-Schärer H,Steinger T

更新日期：2010-01-01 00:00:00

abstract：:Microscopic structures (petrofilaments) may develop during palynological laboratory processing procedures that are superficially similar to secondary wall thickenings and elaters. These filaments form from angular bodies that resemble fungal spores and resin bodies. The angular bodies are a type of hydrocarbon called ...

journal_title：American journal of botany

authors： Graham A,Wood GD,Elsik WC,Speed RC

更新日期：2000-05-01 00:00:00

abstract：PREMISE:Hyperaccumulation of heavy metals in plants has never been documented from Central America or Mexico. Psychotria grandis, P. costivenia, and P. glomerata (Rubiaceae) have been reported to hyperaccumulate nickel in the Greater Antilles, but they also occur widely across the neotropics. The goals of this research...

journal_title：American journal of botany

authors： McCartha GL,Taylor CM,van der Ent A,Echevarria G,Navarrete Gutiérrez DM,Pollard AJ

更新日期：2019-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Phylogenetic incongruence between "gene trees" and "species trees" has been widely acknowledged in phylogenetic research. Conflicts may emerge from several processes including paralogy, hybridization, and incomplete lineage sorting. Although phylogenetic incongruence appears common, its impact on m...

journal_title：American journal of botany

authors： Zhang Q,Feild TS,Antonelli A

更新日期：2015-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Collinsia was the subject of classic biosystematic studies by Garber and colleagues and is increasingly investigated to address major evolutionary questions. Lack of phylogenetic data from more than one gene region and one taxonomic exemplar has left relationships, diversity, and phytogeography of ...

journal_title：American journal of botany

authors： Baldwin BG,Kalisz S,Armbruster WS

更新日期：2011-04-01 00:00:00

abstract：:The geographic distribution of diploid and tetraploid cytotypes and cpDNA haplotypes throughout the entire range of Aucuba japonica was investigated. We measured relative genome size using flow cytometry and sequenced two cpDNA intergenic regions, atpB-rbcL and psbA-trnH (GUG). Two haplotypes include both diploids and...

journal_title：American journal of botany

authors： Ohi T,Kajita T,Murata J

更新日期：2003-11-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multip...

journal_title：American journal of botany

authors： Theis N,Barber NA,Gillespie SD,Hazzard RV,Adler LS

更新日期：2014-08-01 00:00:00

abstract：:Seed and pollen morphology were studied by light microscopy and scanning electron microscopy in 39 North and Central American species of Houstonia (including Hedyotis, but excluding Oldenlandia). Chromosome counts were obtained for eight taxa, of which five lacked previous chromosome data. A chromosome number of n = 1...

journal_title：American journal of botany

authors： Terrell EE,Lewis WH,Robinson H,Nowicke JW

更新日期：1986-01-01 00:00:00