Paleoazolla, a new heterosporous fern from the Upper Cretaceous of Argentina.

abstract：UNLABELLED: PREMISE OF THE STUDY:Specific leaf area (SLA) is a critical component of the leaf economics spectrum, and many functional leaf traits have been empirically demonstrated to covary with SLA. However, a complete understanding of how change in leaf size influences SLA has not yet emerged. • METHODS:To help de...

journal_title：American journal of botany

authors： Price CA,Weitz JS

更新日期：2010-11-01 00:00:00

abstract：:Developmental and physiological studies of roots are frequently limited to a post-germination stage. In Arabidopsis, a developmental change in the root meristem architecture during plant ontogenesis has not previously been studied and is addressed presently. Arabidopsis thaliana have closed root apical organization, i...

journal_title：American journal of botany

authors： Baum SF,Dubrovsky JG,Rost TL

更新日期：2002-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Uplift of the tropical Andes had a significant impact on the diversification of South American flora and fauna. Recent biogeographic inquiries have established patterns of Andean divergence, but investigations on ferns are scant. The fern genus Polystichum Roth (Dryopteridaceae) combines widespread...

journal_title：American journal of botany

authors： McHenry MA,Barrington DS

更新日期：2014-02-01 00:00:00

abstract：:Tribe Macadamieae (91 spp., 16 genera; Proteaceae) is widespread across the southern hemisphere on all major fragments of Gondwana except New Zealand and India. Macadamia is cultivated outside its natural range as a "nut" crop (notably in Hawaii, where it is the principal orchard crop). We sampled seven DNA regions an...

journal_title：American journal of botany

authors： Mast AR,Willis CL,Jones EH,Downs KM,Weston PH

更新日期：2008-07-01 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 OF THE STUDY:Eocene caldera-lake beds at Laguna del Hunco (LH, ca. 52.2 Ma) and Río Pichileufú (RP, ca. 47.7 Ma) in Argentine Patagonia provide copious information about the biological history of Gondwana. Several plant genera from these sites are known as fossils from southern Australia and New Zealand and sur...

journal_title：American journal of botany

authors： Wilf P

更新日期：2012-03-01 00:00:00

abstract：:Members of tribe Vandeae (Orchidaceae) form a large, pantropical clade of horticulturally important epiphytes. Monopodial leafless members of Vandeae have undergone extreme reduction in habit and represent a novel adaptation to the canopy environment in tropical Africa, Asia, and America. To study the evolution of mon...

journal_title：American journal of botany

authors： Carlsward BS,Whitten WM,Williams NH,Bytebier B

更新日期：2006-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Understanding the flexibility of monocot genomes requires a phylogenetic framework, which so far is available for few of the ca. 2800 genera. Here we use a molecular tree for the South American genus Alstroemeria to place karyological information, including fluorescent in situ hybridization (FISH) ...

journal_title：American journal of botany

authors： Chacón J,Sousa A,Baeza CM,Renner SS

更新日期：2012-09-01 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：PREMISE OF THE STUDY:Microsatellite markers were isolated and characterized from Dacryodes edulis (Burseraceae), a tropical rainforests fruit tree of central Africa. METHODS AND RESULTS:Using an enrichment protocol, six microsatellites loci were developed from Dacryodes edulis. We investigated polymorphism using 45 tr...

journal_title：American journal of botany

authors： Benoit L,Born C,Vignes H,Chevallier MH,Todou G,Debain C,Joly HI

更新日期：2011-04-01 00:00:00

abstract：PREMISE OF THE STUDY:Large phylogenies can help shed light on macroevolutionary patterns that inform our understanding of fundamental processes that shape the tree of life. These phylogenies also serve as tools that facilitate other systematic, evolutionary, and ecological analyses. Here we combine genetic data from pu...

journal_title：American journal of botany

authors： Smith SA,Brown JW

更新日期：2018-03-01 00:00:00

abstract：PREMISE OF THE STUDY:Recurrent formation of polyploid taxa is a common observation in many plant groups. Haploid, cytoplasmic genomes like the plastid genome can be used to overcome the problem of homeologous genes and recombination in polyploid taxa. Fragaria (Rosaceae) contains several octo- and decaploid species. We...

journal_title：American journal of botany

authors： Dillenberger MS,Wei N,Tennessen JA,Ashman TL,Liston A

更新日期：2018-05-01 00:00:00

abstract：PREMISE OF THE STUDY:The lycophyte family Selaginellaceae includes approximately 750 herbaceous species worldwide, with the main species richness in the tropics and subtropics. We recently presented a phylogenetic analysis of Selaginellaceae based on DNA sequence data and, with the phylogeny as a framework, the study d...

journal_title：American journal of botany

authors： Weststrand S,Korall P

更新日期：2016-12-01 00:00:00

abstract：PREMISE OF THE STUDY:Reintroductions may be essential to prevent extinction of many critically endangered species. Ideally, reintroduction efforts rely on adjacent source populations, but limited source material may necessitate crossing individuals from different and possibly distant populations. To determine the conse...

journal_title：American journal of botany

authors： Weisenberger LA,Weller SG,Sakai AK

更新日期：2014-11-01 00:00:00

abstract：PREMISE OF THE STUDY:Climate change models for California predict a warmer, drier future, potentially resulting in shorter growing seasons. If phenotypic differences between closely related species currently distributed across a moisture and temperature gradient represent adaptations to their abiotic environment, then ...

journal_title：American journal of botany

authors： Schneider HE,Mazer SJ

更新日期：2016-01-01 00:00:00

abstract：PREMISE:Variation in seedling emergence timing is considered adaptive over the long term in wild populations, but early emergence can result in a fitness advantage. To explore the adaptive significance of seedling emergence timing, it should be studied under realistic conditions and in the context of other traits that ...

journal_title：American journal of botany

authors： Mercer KL,Alexander HM,Snow AA

更新日期：2011-06-01 00:00:00

abstract：:The genus Caltha (Ranunculaceae) consists of 10 species of low-growing, perennial herbs distributed throughout the moist temperate and cold regions of both the Northern and Southern Hemispheres. Traditionally, the species have been divided into two sections: section Psychrophila in the Southern Hemisphere with diploph...

journal_title：American journal of botany

authors： Schuettpelz E,Hoot SB

更新日期：2004-02-01 00:00:00

abstract：:Light propagation and distribution inside leaves have been recognized as important processes influencing photosynthesis. Monochromatic light absorption across the mesophyll was measured using chlorophyll fluorescence generated from illumination of the cut edge (epi-illumination), as well as the adaxial or abaxial surf...

journal_title：American journal of botany

authors： Johnson DM,Smith WK,Vogelmann TC,Brodersen CR

更新日期：2005-09-01 00:00:00

abstract：PREMISE OF THE STUDY:The correct assessment of homology is an important prerequisite for reconstructing phylogenetic relationships and character evolution. Old World Papaveroideae (Papaver, Meconopsis, Roemeria, Stylomecon) show substantial diversity in gynoecium and capsule morphology. In particular, capsules can have...

journal_title：American journal of botany

authors： Kadereit JW,Erbar C

更新日期：2011-08-01 00:00:00

abstract：PREMISE OF THE STUDY:Bio-ontologies are essential tools for accessing and analyzing the rapidly growing pool of plant genomic and phenomic data. Ontologies provide structured vocabularies to support consistent aggregation of data and a semantic framework for automated analyses and reasoning. They are a key component of...

journal_title：American journal of botany

authors： Walls RL,Athreya B,Cooper L,Elser J,Gandolfo MA,Jaiswal P,Mungall CJ,Preece J,Rensing S,Smith B,Stevenson DW

更新日期：2012-08-01 00:00:00

abstract：PREMISE OF THE STUDY:The presence or absence of a functional copy of a plastid gene may reflect relaxed selection, and may be phylogenetically significant, reflecting shared ancestry. In some liverworts, the plastid gene cysA is a pseudogene (inferred to be nonfunctional). We surveyed 63 liverworts from all major clade...

journal_title：American journal of botany

authors： Wickett NJ,Forrest LL,Budke JM,Shaw B,Goffinet B

更新日期：2011-08-01 00:00:00

abstract：:Cacti are a large and diverse group of stem succulents predominantly occurring in warm and arid North and South America. Chloroplast DNA sequences of the trnK intron, including the matK gene, were sequenced for 70 ingroup taxa and two outgroups from the Portulacaceae. In order to improve resolution in three major grou...

journal_title：American journal of botany

authors： Nyffeler R

更新日期：2002-02-01 00:00:00

abstract：:The eudicot order Malpighiales contains ∼16000 species and is the most poorly resolved large rosid clade. To clarify phylogenetic relationships in the order, we used maximum likelihood, Bayesian, and parsimony analyses of DNA sequence data from 13 gene regions, totaling 15604 bp, and representing all three genomic com...

journal_title：American journal of botany

authors： Wurdack KJ,Davis CC

更新日期：2009-08-01 00:00:00

abstract：:Floral morphology of the 13 species of Moringa ranges from actinomorphic flowers with little hypanthium to highly zygomorphic flowers with well-developed hypanthia. Scanning electron and light microscopy were used to identify ontogenetic differences among two actinomorphic and eight zygomorphic species. All species sh...

journal_title：American journal of botany

authors： Olson ME

更新日期：2003-01-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Sphagnum dominates vast expanses of wetland habitats throughout the northern hemisphere and species delimitation within the genus is important because floristic changes associated with a warming global climate may have measureable impacts on large-scale ecological processes. Most north...

journal_title：American journal of botany

authors： Shaw AJ,Shaw B,Johnson MG,Higuchi M,Arikawa T,Ueno T,Devos N

更新日期：2013-06-01 00:00:00

abstract：PREMISE OF THE STUDY:Plant-herbivore networks are highly specialized in their interactions, yet they are highly variable with regard to the relative importance of specific host species for herbivores. How host species traits determine specialization and species strength in this antagonistic network is still an unanswer...

journal_title：American journal of botany

authors： López-Carretero A,Boege K,Díaz-Castelazo C,Domínguez Z,Rico-Gray V

更新日期：2016-08-01 00:00:00

abstract：PREMISE OF THE STUDY:We isolated and characterized microsatellite markers for the California poppy, Eschscholzia californica, which is an invasive species in central Chile. METHODS AND RESULTS:A total of eight polymorphic and six monomorphic loci were developed for the species. Between one and 12 alleles were observed...

journal_title：American journal of botany

authors： Véliz D,Gauci R,Bustamante RO

更新日期：2012-09-01 00:00:00

abstract：:In turnip mitochondria the cox2 gene is partially contained within a 2-kb (kilobase) direct repeat that is the site of homologous recombination events that generate subgenomic molecules. Because of its partial presence within the direct repeat, the turnip cox2 gene exists in four genomic contexts, two on the master ch...

journal_title：American journal of botany

authors： Dong F,Wilson K,Makaroff C

更新日期：1998-02-01 00:00:00

abstract：PREMISE OF THE STUDY:Documented fossil floras in the neotropics are sparse, yet their records provide evidence on the spatial and temporal occurrence of taxa, allowing for testing of biogeographical and diversification scenarios on individual lineages. A new fossil Piper from the Late Cretaceous of Colombia is describe...

journal_title：American journal of botany

authors： Martínez C,Carvalho MR,Madriñán S,Jaramillo CA

更新日期：2015-02-01 00:00:00

abstract：:The taxonomic richness of seed plants at different taxonomic levels was compared between temperate East Asia and North America at both continental and semi-continental scales. In each comparison, land area and latitude range were adjusted to a comparable level between the two continental regions. East Asia is signific...

journal_title：American journal of botany

authors： Qian H

更新日期：2002-11-01 00:00:00