Routes of origin of two recently evolved hybrid taxa: Senecio vulgaris var. hibernicus and York radiate groundsel (Asteraceae).

abstract：:Nuclear DNA contents (4C) were estimated by Feulgen microdensitometry in 27 species of slipper orchids. These data and recent information concerning the molecular systematics of Cypripedioideae allow an interesting re-evaluation of karyotype and genome size variation among slipper orchids in a phylogenetic context. DN...

journal_title：American journal of botany

authors： Cox A,Abdelnour G,Bennett M,Leitch I

更新日期：1998-05-01 00:00:00

abstract：:A conspicuous feature of Vochysiaceae flowers is their single fertile stamen. In some genera, the stamen is in front of a petal, whereas in others it is in front of a sepal. This difference has been attributed to two independent reductions, which implies the stamen is not homologous across the family. The observation ...

journal_title：American journal of botany

authors： Litt A,Stevenson DW

更新日期：2003-11-01 00:00:00

abstract：:Bennettitales is an extinct group of seed plants with reproductive structures that are similar in some respects to both Gnetales and angiosperms, but systematic relationships among the three clades remain controversial. This study summarizes characters of bennettitalean plants and presents new evidence for the structu...

journal_title：American journal of botany

authors： Rothwell GW,Crepet WL,Stockey RA

更新日期：2009-01-01 00:00:00

abstract：:Woody stems comprise a large biological carbon fraction and determine water transport between roots and leaves; their structure and function can influence both carbon and hydrological cycles. While angiosperm wood anatomy and density determine hydraulic conductivity and mechanical strength, little is known about inter...

journal_title：American journal of botany

authors： Zanne AE,Westoby M,Falster DS,Ackerly DD,Loarie SR,Arnold SE,Coomes DA

更新日期：2010-02-01 00:00:00

abstract：:We propose a new method, the leaf measuring-interval index (LMI), to estimate leaf age in morphological and physiological studies of leaves. When the plastochron, the interval between the initiation of successive leaves, is constant, the well-known leaf plastochron index (LPI) provides a robust measure of leaf age. Wh...

journal_title：American journal of botany

authors： Chen CC,Chen H,Chen YR

更新日期：2009-07-01 00:00:00

abstract：PREMISE OF THE STUDY:This paper investigates the occurrence and evolution of aluminum (Al) accumulation within ferns and lycophytes, which is characterized by Al concentrations above 1000 mg·kg-1 in aboveground plant tissues. We hypothesize that this feature is more common in ferns than in angiosperms, and potentially ...

journal_title：American journal of botany

authors： Schmitt M,Mehltreter K,Sundue M,Testo W,Watanabe T,Jansen S

更新日期：2017-04-01 00:00:00

abstract：:Plant tropisms play a fundamental role in shaping the growth form of plants, and these fascinating movements are the focus of this thematic issue of the American Journal of Botany. The issue includes 16 reviews of the current literature and eight original manuscripts written by a diverse group of international experts...

journal_title：American journal of botany

authors： Wyatt SE,Kiss JZ

更新日期：2013-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Global change in temperature and soil nitrogen availability could affect plant community composition, potentially giving an advantage to invasive species compared to native species. We addressed how high temperatures affected CO2 assimilation parameters for invasive Phalaris arundinacea and a sedge...

journal_title：American journal of botany

authors： Waring EF,Holaday AS

更新日期：2017-07-01 00:00:00

abstract：PREMISE OF THE STUDY:Evolutionary and biogeographic history, including past environmental change and diversification processes, are likely to have influenced the expansion, migration, and extinction of populations, creating evolutionary legacy effects that influence regional species pools and the composition of communi...

journal_title：American journal of botany

authors： Cavender-Bares J,Kothari S,Meireles JE,Kaproth MA,Manos PS,Hipp AL

更新日期：2018-03-01 00:00:00

abstract：:Because leaf pubescence of the desert shrub Encelia farinosa increases in response to drought and influences photosynthesis and transpiration, we hypothesized that differences in water availability across the range of this species may result in genetic differentiation for pubescence and associated productivity traits....

journal_title：American journal of botany

authors： Sandquist DR,Ehleringer JR

更新日期：2003-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Self-incompatibility (SI) is a mechanism that prevents inbreeding in many plant species. The mutational breakdown of SI occurs frequently, yet relatively little is known about the evolutionary steps involved in the progressive loss of pistil and pollen SI function. METHODS:In Solanaceae, SI is the...

journal_title：American journal of botany

authors： Markova DN,Petersen JJ,Qin X,Short DR,Valle MJ,Tovar-Méndez A,McClure BA,Chetelat RT

更新日期：2016-10-01 00:00:00

abstract：:Inferring basal relationships among vascular plants poses a major challenge to plant systematists. The divergence events that describe these relationships occurred long ago and considerable homoplasy has since accrued for both molecular and morphological characters. A potential solution is to examine phylogenetic anal...

journal_title：American journal of botany

authors： Wolf P

更新日期：1997-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Geographic differences in flower visitor assemblages might lead to among-population differences in the magnitude and pattern of floral integration. However, the role of current pollinator visitation in shaping the magnitude and pattern of floral trait correlations is still controversial. METHODS:W...

journal_title：American journal of botany

authors： Lázaro A,Santamaría L

更新日期：2016-02-01 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：:The endodermis of different species of the genus Equisetum has different configurations, two or one continuous layers or a sheath only around the vascular bundles. The question whether the endodermis contributes to the mechanical stability of the aerial shoots is investigated in two ways: In a direct approach, the end...

journal_title：American journal of botany

authors： Spatz HC,Emanns A

更新日期：2004-11-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Allometric relationships among the dimensions of leaf cells, cell walls, and tissues, and whole-leaf thickness and area are likely to have key implications for leaf construction and function, but have remained virtually untested, despite the explosion of interest in allometric analysis...

journal_title：American journal of botany

authors： John GP,Scoffoni C,Sack L

更新日期：2013-10-01 00:00:00

abstract：:The tribe Genisteae includes genera of great ecological importance in Mediterranean countries because they are dominant elements of many plant communities. Genetic variation and diversification patterns in Stauracanthus (Genisteae) provide information relevant for the study of the processes of diversification in relat...

journal_title：American journal of botany

authors： Pardo C,Cubas P,Tahiri H

更新日期：2008-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Climate cycles of the Quaternary have impacted plants at a global scale, leaving behind a complex genetic legacy. Species of the northern Rocky Mountains of North America were exposed to more uniform glacial patterns than the central and southern ranges, where synergistic relationships between temp...

journal_title：American journal of botany

authors： Fuller RS,McGlaughlin ME

更新日期：2019-03-01 00:00:00

abstract：:Understanding the role of geography and ecology in species divergence is central to the study of evolutionary diversification. We used climatic, geographic, and biological data from nine wild Andean tomato species to describe each species' ecological niche and to evaluate the likely ecological and geographical modes o...

journal_title：American journal of botany

authors： Nakazato T,Warren DL,Moyle LC

更新日期：2010-04-01 00:00:00

abstract：:A well-integrated plant shows extensive carbohydrate translocation through the plant body. Even in highly integrated plants, however, translocation patterns will be sectorial if vascular tissue restricts carbon movement to sectors along stems. Both integration and sectorial translocation patterns are sensitive to plan...

journal_title：American journal of botany

authors： Preston KA

更新日期：1998-12-01 00:00:00

abstract：PREMISE OF THE STUDY:General relationships among functional traits have been identified across species, but the forces shaping these relationships remain largely unknown. Adopting an approach from evolutionary biology, we studied similarities and differences in intrapopulation trait correlations among locally co-occurr...

journal_title：American journal of botany

authors： Messier J,Violle C,Enquist BJ,Lechowicz MJ,McGill BJ

更新日期：2018-09-01 00:00:00

abstract：PREMISE:Adaptation to harsh edaphic substrates has repeatedly led to the evolution of edaphic specialists and generalists. Yet, it is unclear what factors promote specialization versus generalization. Here, we search for habitat use patterns associated with serpentine endemics (specialists) and serpentine tolerators (g...

journal_title：American journal of botany

authors： Sianta SA,Kay KM

更新日期：2019-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Robust markers are required (inter alia) for assessing origins of Calophyllum inophyllum populations on the Bonin Islands, Japan. Therefore, informative expressed sequence tag (EST)-based microsatellite or simple sequence repeat (SSRs) markers in the species were sought. METHODS AND RESULTS:Using ...

journal_title：American journal of botany

authors： Setsuko S,Uchiyama K,Sugai K,Hanaoka S,Yoshimaru H

更新日期：2012-01-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:The evolution of invasiveness has been extensively studied in natural ecosystems; however, far less is known about the evolution of agricultural invasiveness, despite the major economic impact of weeds on crop productivity. Examining the population structure of recently arisen weeds c...

journal_title：American journal of botany

authors： Waselkov KE,Olsen KM

更新日期：2014-10-01 00:00:00

abstract：PREMISE OF THE STUDY:Pollinator shifts have been implicated as a driver of divergence in angiosperms. We tested the hypothesis that there was a transition from bird- to butterfly pollination in the African genus Clivia (Amaryllidaceae) and investigated how floral traits may have been either modified or retained during ...

journal_title：American journal of botany

authors： Kiepiel I,Johnson SD

更新日期：2014-01-01 00:00:00

abstract：PREMISE OF THE STUDY:Herbivory affects pollination success and reproductive output in plants. However, the different stages in the process from pollination to seed maturation have hardly been investigated within the context of herbivory. Herbivory might affect these stages via its effect on geitonogamous pollination an...

journal_title：American journal of botany

authors： Ghyselen C,Bonte D,Brys R

更新日期：2015-12-01 00:00:00

abstract：:Chromosome numbers and karyotypes of species of Orobanche, Cistanche, and Diphelypaea (Orobanchaceae) were investigated, and 108 chromosome counts of 53 taxa, 19 counted for the first time, are presented with a thorough compilation of previously published data. Additionally, karyotypes of representatives of these gene...

journal_title：American journal of botany

authors： Schneeweiss GM,Palomeque T,Colwell AE,Weiss-Schneeweiss H

更新日期：2004-03-01 00:00:00

abstract：PREMISE OF STUDY:Sequence analyses for Pinaceae have suggested that extant genera diverged in the late Mesozoic. While the fossil record indicates that Pinaceae was highly diverse during the Cretaceous, there are few records of living genera. This description of an anatomically preserved seed cone extends the fossil re...

journal_title：American journal of botany

authors： Klymiuk AA,Stockey RA

更新日期：2012-06-01 00:00:00

abstract：PREMISE:Woody plants with photosynthetic stems are common in the drylands of the world; however, we know little about the origin(s) and geographical distribution of photosynthetic stems. Therefore, we set to answer the following questions: (1) Is stem photosynthesis phylogenetically conserved? (2) Do green-stemmed and ...

journal_title：American journal of botany

authors： Ávila-Lovera E,Garcillán PP

更新日期：2020-12-06 00:00:00

abstract：:The temperature dependence of freezing-induced xylem cavitation was studied in a Chihuahuan desert population of Larrea tridentata (Zygophyllaceae). Field measurements of wood temperature and xylem embolism were combined with anatomical studies and laboratory measurements of embolism in stem and root samples frozen un...

journal_title：American journal of botany

authors： Martínez-Vilalta J,Pockman WT

更新日期：2002-12-01 00:00:00