Herbivory alters the expression of a mixed-mating system.

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：:Welwitschiaceae, a family in the Gnetales, is known today from only one extant species, Welwitschia mirabilis. This species is distributed in the Namibian desert, along the western coast of southern Africa, about 10 km inland from the coast. Very little is known about the fossil record of this family. Lower Cretaceous...

journal_title：American journal of botany

authors： Dilcher DL,Bernardes-De-Oliveira ME,Pons D,Lott TA

更新日期：2005-08-01 00:00:00

abstract：:Seed size and cotyledon morphology are two key juvenile traits that have evolved in response to changes in plant species life-history strategies and habitat associations. Correlations of these traits with each other and with other juvenile traits were examined for 70 species of trees and shrubs in Kibale National Park...

journal_title：American journal of botany

authors： Zanne AE,Chapman CA,Kitajima K

更新日期：2005-06-01 00:00:00

abstract：:The cell division pattern in the apical meristem of Psilotum nudum was examined using epi-illumination microscopy and a paraffin method. In the subterranean axis, about half of the derivative cells of the apical cell produce tetrahedral daughter apical cells by the first three or more oblique divisions. Roughly half o...

journal_title：American journal of botany

authors： Takiguchi Y,Imaichi R,Kato M

更新日期：1997-05-01 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：:The possible pathways of origin of two recently arisen introgressant forms of Senecio vulgaris (i.e., var. hibernicus and York radiate groundsel) were investigated in experimental crosses between tetraploid S. vulgaris var. vulgaris and the normally diploid S. squalidus. Comparison of the morphology of synthesized hyb...

journal_title：American journal of botany

authors： Lowe AJ,Abbott RJ

更新日期：2000-08-01 00:00:00

abstract：:Biparental inbreeding is thought to be a common feature of plant populations with restricted pollen dispersal. It is generally assumed that the inbreeding depression frequently observed to accompany self-fertilization can be extrapolated to the lesser degrees of consanguinity involved in biparental inbreeding, but thi...

journal_title：American journal of botany

authors： Heywood JS

更新日期：1993-05-01 00:00:00

abstract：:Phylogenetic relationships and biogeography of the genus Cerastium were studied using sequences of three noncoding plastid DNA regions (trnL intron, trnL-trnF spacer, and psbA-trnH spacer). A total of 57 Cerastium taxa was analyzed using two species of the putative sister genus Stellaria as outgroups. Maximum parsimon...

journal_title：American journal of botany

authors： Scheen AC,Brochmann C,Brysting AK,Elven R,Morris A,Soltis DE,Soltis PS,Albert VA

更新日期：2004-06-01 00:00:00

abstract：:Cleistogamous capitula formed by Centaurea melitensis display a number of morphological and functional changes with respect to chasmogamous capitula that ensure self-fertilization. Because no studies have hitherto addressed the evolution of cleistogamy in Asteraceae, it was considered useful to ascertain whether these...

journal_title：American journal of botany

authors： Porras R,Muñoz JM

更新日期：2000-07-01 00:00:00

abstract：UNLABELLED:• PREMISE OF THE STUDY:Accurate assessments of biodiversity are paramount for understanding ecosystem processes and adaptation to change. Invasive species often contribute substantially to local biodiversity; correctly identifying and distinguishing invaders is thus necessary to assess their potential impac...

journal_title：American journal of botany

authors： Moffat CE,Ensing DJ,Gaskin JF,De Clerck-Floate RA,Pither J

更新日期：2015-07-01 00:00:00

abstract：:Seeds are useful in distinguishing among extant genera of Vitaceae and provide a good basis for interpretation of fossil remains in reconstructing the evolutionary and phytogeographic history of this putatively basal Rosid family. Seeds of Ampelocissus s.l. including Pterisanthes and Nothocissus are distinguished from...

journal_title：American journal of botany

authors： Chen I,Manchester SR

更新日期：2007-09-01 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：: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：PREMISE:Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerance...

journal_title：American journal of botany

authors： Martino M,Semple JC,Beck JB

更新日期：2020-11-01 00:00:00

abstract：:Multiply sired fruits provide unambiguous evidence that pollen from two or more donors was deposited on a stigma and successfully fertilized ovules. Such multiple paternity within fruits can have important consequences for both parental and offspring fitness, but little is known about the frequency of multiple paterni...

journal_title：American journal of botany

authors： Mitchell RJ,Karron JD,Holmquist KG,Bell JM

更新日期：2005-05-01 00:00:00

abstract：PREMISE OF THE STUDY:Inclusion of fossils in phylogenetic analyses is necessary in order to construct a comprehensive "tree of death" and elucidate evolutionary history of taxa; however, such incorporation of fossils in phylogenetic reconstruction is dependent on the availability and interpretation of extensive morphol...

journal_title：American journal of botany

authors： Smith SY,Iles WJD,Benedict JC,Specht CD

更新日期：2018-08-01 00:00:00

abstract：:The mode of chloroplast DNA (cpDNA) inheritance was investigated in the genus Larrea (Zygophyllaceae) by polymerase chain reaction (PCR) amplification of cpDNA fragments using three pairs of chloroplast universal primers. A total of 20 F(1)s from interspecific crosses among five different taxa in the section Bifolium ...

journal_title：American journal of botany

authors： Yang TW,Yang YA,Xiong Z

更新日期：2000-10-01 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：:The pitchers of the tropical carnivorous plant Nepenthes alata are highly specialized organs for the attraction and capture of insects and absorption of nutrients from them. This study examined the structure and development of these pitchers, with particular focus on the nectaries and digestive glands. Immature pitche...

journal_title：American journal of botany

authors： Owen TP Jr,Lennon KA

更新日期：1999-10-01 00:00:00

abstract：UNLABELLED: PREMISE OF THE STUDY:Fungal plant pathogens exert much of their effect on plant cells through alterations in the host cell walls. However, obtaining biochemical proof for this change is difficult because of the relatively small number of cells that are affected by the pathogen relative to the bulk of host ...

journal_title：American journal of botany

authors： Bowling AJ,Vaughn KC,Hoagland RE,Stetina K,Boyette CD

更新日期：2010-12-01 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：:Parsimony, likelihood, and Bayesian analyses of nuclear ITS and plastid trnL-F DNA sequence data are presented for the giant genus Croton (Euphorbiaceae s.s.) and related taxa. Sampling comprises 88 taxa, including 78 of the estimated 1223 species and 29 of the 40 sections previously recognized of Croton. It also incl...

journal_title：American journal of botany

authors： Berry PE,Hipp AL,Wurdack KJ,Van Ee B,Riina R

更新日期：2005-09-01 00:00:00

abstract：:Up to 22% of plant species are the result of breeding among species-hybridization-directly conflicting with the prediction that hybrids, compared to parental species, are intermediate in character and of low fitness and little consequence. Few studies, however, have compared the fitness of hybrids and parental species...

journal_title：American journal of botany

authors： Tierney DA,Wardle GM

更新日期：2008-02-01 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: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：PREMISE OF THE STUDY:To enhance our knowledge of the diversity of microalgae, a phycological survey of the Canary Islands (Spain) was undertaken. Here we report the discovery of a (semi)terrestrial green filamentous alga isolated from a steep volcanic canyon on La Palma. This alga is continually exposed to changing wea...

journal_title：American journal of botany

authors： Caisová L,Reyes CP,Álamo VC,Quintana AM,Surek B,Melkonian M

更新日期：2015-09-01 00:00:00

abstract：:Patterns of biodiversity are ultimately the product of speciation and extinction. Speciation serves as the biodiversity pump while extinction serves as the agent that culls global to local levels of biodiversity. Linking these central processes to global and local patterns of biodiversity is a key challenge in both ec...

journal_title：American journal of botany

authors： Swenson NG

更新日期：2011-03-01 00:00:00

abstract：:Serpentine soils are a model system for the study of plant adaptation, speciation, and species interactions. Serpentine soil is an edaphically stressful, low productivity soil type that hosts stunted vegetation and a spectacular level of plant endemism. One of the first papers on serpentine plant endemism was by Arthu...

journal_title：American journal of botany

authors： Anacker BL

更新日期：2014-02-01 00:00:00

abstract：:Accurate estimates of inbreeding depression are necessary in order to predict the evolutionary dynamics of a population, but many studies estimate inbreeding depression based solely on components of female function such as fruit set, seed set, and seed quality. Because total fitness is achieved through both male and f...

journal_title：American journal of botany

authors： Hayes CN,Winsor JA,Stephenson AG

更新日期：2005-01-01 00:00:00

abstract：:Polyploids have significantly influenced angiosperm evolution. Understanding the genetic consequences of polyploidy is advanced by studies on synthetic allopolyploids that mimic natural species. In Nicotiana, Burk (1973) and Kostoff (1938) generated synthetic tobacco (N. tabacum) using the parents ♀N. sylvestris × ♂N....

journal_title：American journal of botany

authors： Lim KY,Souckova-Skalicka K,Sarasan V,Clarkson JJ,Chase MW,Kovarik A,Leitch AR

更新日期：2006-06-01 00:00:00