bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐temperature, acid‐hydrolyzed remains of Polytrichum (Musci, Polytrichaceae) resemble enigmatic Silurian‐Devonian tubular microfossils
Authors: Kodner Robin B. , Graham Linda E.
Published: February 2007

Gametophytes and sporophyte components of two species of the evolutionarily early‐divergent moss Polytrichum were separately subjected to high‐temperature acid hydrolysis, and remains were examined by fluorescence microscopy and scanning electron microscopy. Remains included fragments of capsule, seta, leaves, stems, and calyptra. Cell walls of all remains were autofluorescent in violet and UV excitation, suggesting occurrence of resistant polyphenolic compounds. Calyptras of both species dissociated into smooth‐ walled, acutely branched filamentous associations of tubular cells with distinctively thickened cell junctions. In these aspects and measurements of wall dimensions made from SEMs, the hydrolysis‐resistant Polytrichum calyptra remains were similar to several tubular microfossils described from Silurian and Lower Devonian deposits, whose provenance is unknown or ascribed to fungi. Our data suggest the possibility that at least some ancient tubular microfossils might have originated from Polytrichum‐like early mosses. They add to increasing evidence that bryophytes left microfossil evidence for their presence millions of years earlier than is indicated by their macrofossil record.
Fossil flowers of ericalean affinity from the Late Cretaceous of Southern Sweden
Authors: Schönenberger Jürg , Friis Else Marie
Published: February 2007

Charcoalified fossil flowers of a new genus and species (Paradinandra suecica) with affinities to Ericales s.l. (sensu lato) are described from the Late Cretaceous (Santonian‐Campanian) from Southern Sweden. The flowers are pentamerous, hypogynous, and actinomorphic. Aestivation of sepals and petals is imbricate‐quincuncial. The androecium consists of an outer whorl with single episepalous stamens and an inner whorl with paired epipetalous stamens. Pollen is small and probably tricolpate. Three carpels form a syncarpous ovary with numerous campylotropous ovules on parietal placentae. The styles are free for most of their length. The structure of mature fruits and seeds is unknown. Clear distinction of sepals and petals, possible dehiscence of anthers by restricted slits, presence of a nectary, and the general floral construction (salverform corolla) with a canalized access to the floral center clearly indicate insect pollination of the fossil flowers. Comparisons with extant taxa demonstrate that Paradinandra suecica shares many similarities with Ericales s.l. and in particular with members of Ternstroemiaceae, Theaceae, and Actinidiaceae. However, it is neither identical to any one genus of these families nor to any of the previously described ericalean taxa from the Cretaceous and thus provides further evidence of the diversity of Cretaceous ericalean plants.
Bladder function in Utricularia purpurea (Lentibulariaceae): is carnivory important?
Authors: Richards Jennifer H.
Published: February 2007

Utricularia purpurea is a rootless, free‐floating, aquatic, carnivorous plant. I quantified biomass investment in U. purpurea traps and determined when traps begin to function and what they trap in natural habitats. In the Everglades of south Florida, plants invest an average of 26% of their biomass in bladders, although bladder number varies among sites and over time. Leaves begin trapping as they mature, and on leaves one whorl older than the most recently matured leaves, almost 100% of bladders have allochthonous material. Despite the substantial investment in their biomass, bladders capture few aquatic microinvertebrates. Almost all mature bladders, however, have living communities of algae, zooplankton, and associated debris. These results support the hypotheses that the important association in U. purpurea bladders is a mutualism rather than a predator–prey interaction and that the major benefit to the plants from bladders is derived from this community.
Dead Bodies in the Postwar Discourse of Identity in Seventeenth-Century Korea: Subversion and Literary Production in the Private Sector
Authors: Haboush Jahyun Kim
Published: February 2007

As katherine verdery notes, dead bodies have had political lives in virtually every civilization since antiquity. They frequently emerge as powerful metaphors of change, especially after a time of crisis when the meaning of political symbols is redefined. This is vividly exemplified by what happened to the exhumed bodies of various ethnic groups in the former Yugoslavia (Verdery 1999, 1–22). Postwar discourse is another site in which dead bodies frequently emerge as metaphors. Some of the most unforgettable sights concerning World War II are pictures of huge piles of exhumed human bodies from the mass graves of Jews. We know that these are not skeletons of those who have died natural deaths because these images have often been shown along with the pictures of inmates of the concentration and death camps, emaciated to the point of nonrecognition as living human beings. Through this process, the pictures have acquired an independent status as encoded language: they signify unbelievable evil committed against humanity, and they display the moral weakness of the rest of humanity that failed to resist and end such atrocities.
What Is Evolution? A Response to Bamforth
Authors: O'Brien Michael J. , Lyman R. Lee , Leonard Robert D.
Published: February 2007

Douglas Bamforth's recent paper in American Antiquity, “Evidence and Metaphor in Evolutionary Archaeology,” charges that Darwinism has little to offer archaeology except in a metaphorical sense. Specifically, Bamforth claims that arguments that allegedly link evolutionary processes to the archaeological record are unsustainable. Given Bamforth's narrow view of evolution—that it must be defined strictly in terms of changes in gene frequency—he is correct. But no biologist or paleontologist would agree with Bamforth"s claim that evolution is a process that must he viewed fundamentally at the microlevel. Evolutionary archaeology has argued that materials in the archaeological record are phenotypic in the same way that hard parts of organisms are. Thus changes in the frequencies of archaeological variants can be used to monitor the effects of selection and drift on the makers and users of those materials. Bamforth views this extension of the human phenotype as metaphorical because to him artifacts are not somatic features, meaning their production and use are not entirely controlled by genetic transmission. He misses the critical point that in terms of evolution, culture is as significant a transmission system as genes are. There is nothing metaphorical about viewing cultural transmission from a Darwinian point of view.
Genetic relatedness among developing seeds and intra fruit seed abortion inDalbergia sissoo(Fabaceae)
Authors: Mohana G. S. , Shaanker R. Uma , Ganeshaiah K. N. , Dayanandan S.
Published: February 2007

Dalbergia sissoo, a wind‐dispersed tropical tree, exhibits high intrafruit seed abortion. Of the four to five ovules in the flower, generally one and occasionally two or three develop to maturity. It has been proposed that the seed abortion is a consequence of intense sibling competition for maternal resources and that this competition occurs as an inverse function of the genetic relatedness among the developing seeds. Accordingly, developing seeds compete intensely when they are genetically less related but tend to develop together when genetically more related. We tested this hypothesis by comparing the genetic similarity among the pairs of seeds developing within a pod with that among (a) random pairs from the pool of all seeds, (b) random pairs from single‐seeded pods, and (c) random pairs from two‐seeded pods, using both randomly amplified polymorphic DNA (RAPD) and isozymes in five trees. We found that the pairs of seeds developing within a pod are genetically more similar than any random pairs of seeds in a tree. Thus the formation of two‐seeded pods appear to be associated with increased genetic relatedness among the developing seeds. We discuss the results in the context of possible fitness advantages and then discuss the possible mechanisms that promote tolerance among related seeds.
The effect of maternal photoperiod on seasonal dormancy inArabidopsis thaliana(Brassicaceae)
Authors: Munir Jamalah , Dorn Lisa A. , Donohue Kathleen , Schmitt Johanna
Published: February 2007

The maternal photoperiod at the time of seed maturation can predict the seasonal conditions of newly dispersed seeds. We investigated the effects of maternal photoperiod on seasonal dormancy inArabidopsis thalianausing a set of F6 recombinant inbred lines derived from a cross between individuals from two natural populations (Cal‐0 and Tac‐0) differing in cold requirements for germination. We grew 40 Cal × Tac lines in a long‐day photoperiod (8 h of full spectrum light plus 8 h of low‐fluence incandescent light) and a short‐day photoperiod (8 h full spectrum light). We then exposed seeds from each family and maternal photoperiod to either a cold stratification treatment (4°C, 21 d) or no cold stratification. Both maternal photoperiod and progeny stratification influenced the percentage of seeds that germinated and the speed of germination. The short‐day photoperiod caused increased responsiveness to stratification, with higher germination percentages and speeds in stratified seeds. Stratification influenced the expression of maternal photoperiod effects, such that short days increased germination percentage and speed in stratified seeds but inhibited germination in unstratified seeds. Families differed significantly in their plasticity to maternal photoperiod and stratification, but genetic variation for plasticity to maternal photoperiod was expressed only in unstratified seeds. Because the expression of maternal photoperiod effects and genetic variation for photoperiod effects depended on progeny stratification, the evolution of these maternal effects will depend on the seasonal environment experienced by progeny.
Molecular, physiological, and growth responses to sodium stress in C4 grasses from a soil salinity gradient in the Serengeti ecosystem
Authors: Hamilton E. William , McNaughton Samuel J. , Coleman James S.
Published: February 2007

The concentration of soil sodium (Na) is an important factor that influences species distribution in the Serengeti short‐grass plains, Tanzania. Experiments were conducted to characterize physiological (growth, photosynthetic, nutrients, and water relations) and molecular (heat shock proteins and organic solutes) responses to high soil sodium in four Serengeti C4 grasses. The species tested were Andropogon greenwayi and three species of Sporobulus, S. ioclados, S. kentrophyllus and S. spicatus. Andropogon greenwayi occurs on locations with low soil Na concentrations, S. ioclados on low to moderate, S. kentrophyllus moderate to high, and S. spicatus on soils with high Na concentration.

Among all four species, short‐term physiological and molecular responses to Na treatments (0, 100, and 400 mmol/L Na) were correlated with their field soil Na concentrations. Sporobulus kentrophyllus and S. spicatus exhibited rapid molecular induction of heat shock proteins in response to experimental soil Na treatments within 24 h and had increased levels of proline within 96 h in contrast to A. greenwayi and S. ioclados. Photosynthetic rates and water relations were positively correlated with field soil Na concentrations and Hsp induction was clearly associated with photosynthetic tolerance. Long‐term (6 wk) responses of the four species to Na treatment were consistent with the short‐term responses to Na. Species that occur on low Na soils in the field did not survive past week 1 when treated with 400 mmol/L Na and exhibited significant reductions in biomass when treated with 100 mmol/L Na. Reduced biomass was associated with increased shoot tissue Na concentrations, and thus Na tolerance correlated with the Na concentrations of field leaf tissue. The results demonstrate that the community distribution of these species reflects their Na tolerance and that the observed physiological and molecular responses in tolerant species may have adaptive significance.
Evolutionary trends in safety factors against wind‐induced stem failure
Authors: Niklas Karl J. , Speck Thomas
Published: February 2007

We explore the hypothesis that the safety factor against wind‐induced stem failure remained high during early land plant evolution despite an evolutionary increase in height with concomitant increases in wind‐induced drag forces, bending stresses, and moments. This hypothesis was examined for 17 Paleozoic plant species assuming that each (1) existed in a densely packed community of conspecifics with equivalent height, (2) coped with the same wind profile (where ambient wind speed decreased toward ground level), but (3) had different within‐canopy wind speeds depending on plant height and general morphology. Drag forces, stresses, and moments were computed, and a safety factor was calculated for each taxon using the quotient of its stem‐tissue breaking stress and maximum wind‐induced bending stress.

The highest factors of safety were calculated among the most ancient rhyniophyte and zosterophyllophyte species examined (e.g., Rhynia and Gosslingia), and, on average, decreased among the taller and geologically younger species. The tallest species examined (e.g., Archaeopteris and Diaphorodendron) had safety factors equal to or higher than those of some of their presumed ancestors (e.g., Psilophyton and Leclercqia). These trends were statistically more robust among rhyniophytes and their presumed descendants.

Even though the results comply with the hypothesis, numerous limitations of our protocol exist (e.g., the requirement for reliable whole‐plant reconstructions). These are discussed in terms of our theory. Nonetheless, we believe our theory and protocol afford a reasonable opportunity to explore the effects of wind on early plant evolution.
Assessing the potential for the stomatal characters of extant and fossil Ginkgo leaves to signal atmospheric CO2 change
Authors: Chen Li‐Qun , Li Cheng‐Sen , Chaloner William G. , Beerling David J. , Sun Qi‐Gao , Collinson Margaret E. , Mitchell Peter L.
Published: February 2007

The stomatal density and index of fossil Ginkgo leaves (Early Jurassic to Early Cretaceous) have been investigated to test whether these plant fossils provide evidence for CO2‐rich atmosphere in the Mesozoic. We first assessed five sources of natural variation in the stomatal density and index of extant Gingko biloba leaves: (1) timing of leaf maturation, (2) young vs. fully developed leaves, (3) short shoots vs. long shoots, (4) position in the canopy, and (5) male vs. female trees. Our analysis indicated that some significant differences in leaf stomatal density and index were evident arising from these considerations. However, this variability was considerably less than the difference in leaf stomatal density and index between modern and fossil samples, with the stomatal index of four species of Mesozoic Ginkgo (G. coriacea, G. huttoni, G. yimaensis, and G. obrutschewii) 60–40% lower than the modern values recorded in this study for extant G. biloba. Calculated as stomatal ratios (the stomatal index of the fossil leaves relative to the modern value), the values generally tracked the CO2 variations predicted by a long‐term carbon cycle model confirming the utility of this plant group to provide a reasonable measure of ancient atmospheric CO2 change.
Dipteronia (Sapindaceae) from the Tertiary of North America and implications for the phytogeographic history of the Aceroideae
Authors: McClain Amy M. , Manchester Steven R.
Published: February 2007

The fossil record of Dipteronia, the sister genus of Acer, is reviewed based on diagnostic winged fruits from the Tertiary of western North America. Today the genus is endemic to eastern Asia with two extant species in central and southern China, but it is well represented in the Tertiary of western North America, ranging from the Paleocene to the Oligocene with the greatest number of occurrences in the middle to late Eocene. There are no known fossil occurrences outside of North America. The fossil fruits, assigned to the new species D. brownii sp. nov., are smaller than those of both living species and were tricarpellate as well as bicarpellate in contrast to the modern species, which are almost exclusively bicarpellate. The tricarpellate condition may be plesiomorphic for Dipteronia and perhaps Aceroideae. The area of origin for Dipteronia is unknown, but it seems likely to have been either Asia or North America, with the genus crossing Beringia in the Paleogene.
Reproductive assurance and the evolutionary ecology of self‐pollination in Clarkia xantiana (Onagraceae)
Authors: Fausto James A. , Eckhart Vincent M. , Geber Monica A.
Published: February 2007

The reproductive assurance hypothesis posits that selection favors self‐pollination in flowering plants where mates and/or pollinators are scarce. A corollary is that self‐pollinating populations are expected to be superior colonizers of mate‐ and pollinator‐scarce environments. The California annual Clarkia xantiana includes outcrossing populations (ssp. xantiana) and autogamously self‐pollinating populations (ssp. parviflora). Outcrossing is ancestral, and the subspecies have parapatric distributions with a narrow contact zone. We tested aspects of the reproductive assurance hypothesis by examining geographic and subspecies variation in the densities of mates and pollinators (native bees) and the density dependence of pollinator visitation and pollen receipt. Plant and flower densities, pollinator density, and pollinator visitation rates were lowest in the region of exclusively self‐pollinating populations. Pollinator assemblages there lacked Clarkia‐associated pollinator taxa that were common elsewhere. Self‐pollinating populations in the contact zone generally had densities and visitation rates intermediate between allopatric self‐pollinating populations and outcrossing populations. Visitation rate and pollen receipt increased significantly with plant density. These findings suggest that selection for reproductive assurance influenced the origin of self‐pollination and/or that reproductive assurance influenced the geographic distribution of self‐pollination. Geographic variation in pollinator assemblages may have generated variation in the value of reproductive assurance.
Species relationships in Lactuca s.l. (Lactuceae, Asteraceae) inferred from AFLP fingerprints
Authors: Koopman Wim J. M. , Zevenbergen Martin J. , Van den Berg Ronald G.
Published: February 2007

An AFLP data set comprising 95 accessions from 20 species of Lactuca s.l. (sensu lato) and related genera was generated using the primer combinations E35/M48 and E35/M49. In phenetic analyses of a data subset, clustering with UPGMA based on Jaccard's similarity coefficient resulted in the highest cophenetic correlation, and the results were comparable to those of a principal coordinates analysis. In analyses of the total data set, phenetic and cladistic analyses showed similar tree topologies for the well‐supported parts of the trees. The validity of cladistic analysis of AFLP data is discussed. The results do not support a distinction among the serriola‐like species L. sativa, L. serriola, L. dregeana, and L. altaica, which is in line with previous results. Therefore, we postulate that these species are conspecific. The serriola‐like species L. aculeata occupies a clearly separate position, making it an ideal outgroup for studies of the closest relatives of L. sativa. The subsect. Lactuca as a group is well supported by our data, but the positions of L. saligna and L. virosa relative to the serriola‐like species remain unclear. The close relationship between the sect. Mulgedium species L. tatarica and L. sibirica is corroborated by the present AFLP results and by additional crossability data.
Thrips pollination of androdioeciousCastilla elastica(Moraceae) in a seasonal tropical forest
Authors: Sakai Shoko
Published: February 2007

Androdioecy is a rare sexual system in nature, as predicted theoretically. Among the androecious species reported so far,Castilla elastica(Moraceae) is unique in that flowers are unisexual and staminate and pistillate flowers on cosexual plants are produced on different inflorescences. In addition, inflorescence structure of staminate inflorescences on males and staminate and pistillate inflorescences on cosexes is markedly different. Staminate inflorescences on males are bivalvate, while staminate inflorescences on cosexes are “fig‐like” and urceolate. Pistillate inflorescences are discoidal. The difference may reflect different roles and requirements of the three inflorescences in pollination and protection from herbivores. This study reports thrips pollination ofC. elastica, demonstrated by a pollinator introduction experiment. Thrips pollination of the species may be an example of mutualism originating from plant–herbivore interactions. In the Moraceae, shifts from simple herbivores on flowers to pollinators might have occurred many times, evolving into diverse pollination systems including the fig–fig wasp mutualism. The family, of which little is known about pollination systems, provides interesting and unique opportunities to study evolution of pollination systems and roles of nonpollinating associates of inflorescences.
Life history ofAcrosiphonia(Codiolales, Chlorophyta) in southwestern British Columbia, Canada
Authors: Sussmann Andrea V. , DeWreede Robert E.
Published: February 2007

This study establishes the phenology of the alternate life history phases of the green algaAcrosiphoniain British Columbia, Canada. Free‐living, filamentous plants are seasonal, March–July, with peak percent cover (10%) in April. Plants are fertile immediately after establishment. The unicells, previously identified asChlorochytrium inclusumandCodiolum petrocelidis, are the sporophyte phase ofAcrosiphonia.‘Chlorochytrium,’ spherical and 160–280 μm in diameter, colonizes the foliose red algaMazzaella splendens1 mo after filamentousAcrosiphoniaplants appear. Maximum density (53 ‘Chlorochytrium’ cells/cm2of blade) was recorded in May. ‘Codiolum,’ on the other hand, is stalked (the vesicle measures 150 × 50 μm) and colonizes the red algal crustPetrocelis.Peak density (22 400 ‘Codiolum’ cells/cm2of crust) was recorded 2 mo after ‘Chlorochytrium’ density peaked. The endophytes survive high summer temperatures, which correlate with death of the free‐living plants, and overwinter in their hosts. Zoospore release in late winter corresponds to decreased host abundance, suggesting the endophytes have evolved a strategy whereby duration in the host is synchronized with host seasonality. A bet‐hedging strategy is proposed forAcrosiphonia's life history: two morphologically different phases have adapted to a seasonally variable environment, with the sporophyte phase capable of colonizing two different hosts.
Studies in Neotropical Paleobotany. XV. A Mio‐Pliocene palynoflora from the Eastern Cordillera, Bolivia: implications for the uplift history of the Central Andes
Authors: Graham Alan , Gregory‐Wodzicki Kathryn M. , Wright Kari L.
Published: February 2007

An assemblage of 33 fossil pollen and spores, recovered from the 3600‐m high Pislepampa locality of E. W. Berry, Eastern Cordillera, Bolivia, adds considerably to our knowledge of three aspects of the region in late Neogene time: (1) the paleovegetation, (2) the paleoclimate, and (3) the paleoelevation of the Central Andes. The plant microfossils recognized are Isoetes, Lycopodium (three types), Cnemidaria, Cyathea (three types), Grammitis, Hymenophyllum, Pteris, trilete fern spores (two types), Danaea, monolete fern spores (four types), Podocarpus, Gramineae, Palmae, Ilex, cf. Oreopanax, Cavanillesia, cf. Pereskia, Compositae (three types), Ericaceae, Tetrorchidium, and unknowns (three types). The diversity of the Compositae suggest that this flora has a maximum age around the Miocene‐Pliocene boundary, that is, 6–7 million years. All members of the paleocommunity presently grow in the bosque montano húmedo (cloud forest) along the eastern slope of the Central Andes of Bolivia, which occurs between MATs (mean annual temperatures) of ∼10° and 20°C. The Pislepampa flora probably represents the lower limits of this forest because the fossil leaves collected by Berry from the same locality all have entire margins, suggesting that the flora grew near the cloud forest–tropical forest transition. Presently, the lower limit of the cloud forest forest has MATs of ∼20°C, a mean annual precipitation between 1000 and 1500 mm, and that part containing most of the identified genera of fossil pollen is found at elevations ∼1200–1400 m. These conditions are thus inferred for the Pislepampa flora; however, because of the uncertainty of the magnitude of global climate change and of possible changes in the ecological range of plant genera, we estimate an error of at least ±1000 m for the paleoelevation estimate. When the total uplift is corrected for probable amounts of erosionally driven isostatic rebound, the paleoelevation estimate suggests that from one‐third to one‐half of the uplift of the Eastern Cordillera had occurred by the beginning of the Pliocene. This estimate is consistent with other paleoelevation estimates from the Central Andes.
Variation in the breeding behavior of the dry forest treeEnterolobium cyclocarpum(guanacaste) in Costa Rica
Authors: Rocha Oscar J. , Aguilar Gabriel
Published: February 2007

We studied the breeding systems of four populations ofEnterolobium cyclocarpum(guanacaste, earpod tree) in Costa Rica. Multilocus estimates of the outcrossing rate indicate thatE. cyclocarpumis a predominant outcrossing species (tmranged between 0.881 and 0.901) and biparental inbreeding is low (range between 0.058 and 0.079). Overall, our analyses showed significant differences in the gene frequencies between pollen and ovules and significant differences in pollen gene frequencies between the four populations. We also found significant differences in the pollen gene frequencies calculated for single trees in the same population. Outcrossing rates and pollen gene frequencies varied in two consecutive years in two populations ofE. cyclocarpum.The correlated mating model revealed that there are differences in the correlation of paternity between populations and years. These findings indicate that there is variation in the average number of trees that father the seed crop of each tree and/or that some fathers are overrepresented in the seed crop of each tree. The implication of these findings for the development of strategies for conservation and management of this species are discussed.
Reproductive biology of the dry forest treeEnterolobium cyclocarpum(guanacaste) in Costa Rica: a comparison between trees left in pastures and trees in continuous forest
Authors: Rocha Oscar J. , Aguilar Gabriel
Published: February 2007

We compared the rate of pollen deposition, the likelihood of fruit production, the number of seeds per fruit, the outcrossing rate, and the progeny vigor of the tropical dry forest treeEnterolobium cyclocarpumfor individuals in pastures vs. individuals in continuous forest. We found that flowers from trees growing in continuous forests were more likely to have pollen deposited on their stigmas than flowers from trees in pastures (52.1 vs. 32.3%, respectively). We also found that trees from continuous forests were almost six times more likely to set fruits and produce more seeds per fruit than trees in pastures. Morever, progeny from trees in continuous forests were, on average, more vigorous than the progeny from trees in pastures, as indicated by 12 of 16 indicators of plant vigor. However, there was no significant difference in the multilocus estimate of the outcrossing rate between the two groups of trees (tm = 1.00 and 0.99 for trees from continuous forest and trees from pastures, respectively). But there are differences in the correlation of paternity between the progeny of the two groups, where the progeny from trees in pastures showed a lower correlation of paternity than progeny of trees from continuous forests (rp= 0.104 andrp= 0.189, respectively). We argue that the mechanisms that regulate progeny vigor are disrupted in trees from pastures. We discuss the implications of these findings for the conservation ofE. cyclocarpum.
Pollination limitation to reproductive success in the Missouri evening primrose, Oenothera macrocarpa (Onagraceae)
Authors: Moody‐Weis Jennifer M. , Heywood John S.
Published: February 2007

Habitat fragmentation may result in plant populations that are less attractive to pollinators and thus susceptible to reduced reproductive output due to pollination limitation. Pollination limitation was investigated in three Missouri populations of Oenothera macrocarpa, a hawk‐moth‐pollinated, perennial herb. The populations represented extremes in size and habitat quality. Following supplemental pollination, mean fertilization success (proportion of ovules fertilized) across populations increased from 24.3 to 44.8% and mean seed set (proportion of ovules that matured into seed) increased from 14.7 to 27.9%. These increases were statistically significant in two of the three populations. Failure to achieve 100% fertilization and seed set following supplementation indicates that other factors, in addition to pollination, were limiting to female reproductive success. Fruit set was pollination limited in only one population. Fruits matured with as few as one seed, suggesting that fruit set was not resource limited. The degree of pollination limitation was greatest in the most disturbed population. The population located in the highest‐quality habitat was not significantly pollination limited. This suggests that pollination limitation is occurring, at least in part, because of reduced pollinator activity in degraded habitats.
Evidence of a mycorrhizal mechanism for the adaptation of Andropogon gerardii (Poaceae) to high‐ and low‐nutrient prairies
Authors: Schultz Peggy A. , Michael Miller R. , Jastrow Julie D. , Rivetta Claudia V. , Bever James D.
Published: February 2007

Andropogon gerardii seed obtained from Kansas and Illinois was grown in a controlled environment in their own and each other's soils, with and without arbuscular mycorrhizal fungi (AMF). Each ecotype grew comparatively better in its own soil indicating adaptation to its soil of origin. Overall, A. gerardii benefited more from AMF in low‐nutrient Kansas soil than Illinois soil. The two ecotypes, however, did not benefit equally from mycorrhizal infection. The Kansas ecotype was three times more responsive to mycorrhizal infection in the Kansas soil than was the Illinois ecotype. Our results indicate that plant adaptation to the nutrient levels of their local soils is likely to be due, at least in part, to a shift in their dependence on mycorrhizal fungi. The Illinois ecotype of A. gerardii has evolved a reduced dependence upon these fungi and greater reliance on a more highly branched root system. In contrast, the Kansas ecotype had a significantly coarser root system and invested proportionately greater carbon in the symbiotic association with AMF as measured by spore production. This study provides the first demonstration that plants can adapt to changing soil nutrient levels by shifting their dependence on AMF. This result has broad implications for our understanding of the role of these fungi in agricultural systems.
Rice and Phragmites: effects of organic acids on growth, root permeability, and radial oxygen loss to the rhizosphere
Authors: Armstrong Jean , Armstrong William
Published: February 2007

Young Phragmites plants were grown in two cocktails of monocarboxylic acids (C1–C5) at pH 6, where the concentration of each acid was innocuous and the total undissociated (potentially toxic) concentrations were 0.35 mmol/L and 0.42 mmol/L. Rice plants were subjected to 1.5 mmol/L acetic acid at pH 4.5 (undissociated concentration = 1.05 mmol/L). In Phragmites, each cocktail curtailed root growth especially and induced premature shoot senescence. In both species, after 3–5 d of treatment, radial oxygen loss (ROL) from apical regions of adventitious roots, and from Phragmites laterals, was reduced to very low values and associated with cell wall lignification and suberization in the surface cell layers. At later stages of treatment, rice responded to acetic acid in similar ways to Phragmites, with the development of intercellular and callus type occlusions in the gas space system, vascular blockages, and the failure of laterals to emerge. The results are relevant to the supply of oxygen from Phragmites roots to sediments for the phytopurification of waste waters, to the efflux of methane and carbon dioxide from wetlands, and to rice cultivation.
A rare continual flowering strategy and its influence on offspring quality in a gynodioecious plant
Authors: Wolfe Lorne M. , Burns Janet L.
Published: February 2007

The majority of angiosperms have a single annual bout of reproduction; species that flower continually throughout the year are rare. Ochradenus baccatus is a gynodioecious, desert shrub whose principal flowering period is associated with the winter rains, although large individuals also remain in flower during the hot, dry summer. The goal of this study was to examine the reproductive consequences of continual flowering in a large population of O. baccatus in Israel. Over the two years of this study, 60% of individuals flowered continuously. The number of fruit and seeds per fruit were greater in winter. Winter seeds were ∼12% heavier than summer seeds and had significantly higher germination rates (80 vs. 60%, respectively). Although summer seeds were smaller and less likely to germinate, we propose that the benefit derived from their production lies in their ability to capitalize on the first winter rains. These early rain events provide a head start on establishment and growth in the hostile desert environment. Plants that delay reproduction until the onset of rains risk having their offspring face the dry conditions of spring and summer.
Is breaking up hard to do? Breakage, growth, and survival in the parasitic clonal plantCuscuta corymbosa(Convolvulaceae)
Authors: Kelly Colleen K. , Harris Daniel , Perez‐Ishiwara Ruben
Published: February 2007

In a tripartite exploration of the effects of traumatic breakage in the parasitic clonal plantCuscuta corymbosa, experimental breakage had significant negative effects upon stem extension of ramets distal to a break and the level of that effect depended upon the number of ramets in the severed fragment. Regular monitoring of clonal individuals transplanted onto naturally occurring, native host species revealed that breakage in individuals growing under natural conditions ranged from 2 to 66% of all interramet connections and significantly affected distance between ramets and stolon generation in ramets associated with a break. Simulations revealed that these responses to breakage would significantly change the “shape” of a clonal individual in a manner capable of affecting probabilities of encounter with patchily distributed resources. Nonetheless, the observed levels of breakage had no discernible effect on biomass accumulation, although individuals that survived into the dry season and thus gained the potential to reproduce in additional seasons had a significantly lower rate of breakage than those that did not. We suggest that the lack of a relationship between breakage and within‐season biomass accumulation is an indication that parasite response to breakage is gauged to expected levels of breakage for the habitat. We note that the capacity of ramets to survive disconnection significantly decreased the loss of tissue that would occur if subunits did not possess the potential to function independently.
The CANZ Approach to Legal History
Authors: Karsten Peter
Published: February 2007

The first quality the reader may have noted about these two essays is that they both deal with the question of the legal rights of marriage partners to the economic fruits of one another's labor. But inasmuch as this was only one of several issues addressed by Bruce Kercher, I see it only as an interesting coincidence. Somewhat more noteworthy is the difference between their methodologies: Golder and Kirkby's engagingly crafted socio-legal analysis beautifully illustrates the “thick description” virtues of a case study of litigation, reform agitation and legislation, while Kercher gets us well beyond Alan Atkinson's pioneering study of his subject by carefully drawing evidence unavailable to Atkinson from some of the many cases that he and his research assistants have uncovered from manuscript and newspaper records over the past several years (decisions of the Supreme Courts of New South Wales and VanDieman's Land that are steadily becoming available to us all on two websites). Needless to say, both methodologies “work.”
Phylogenetic relationships among species of the neotropical genus Randia (Rubiaceae, Gardenieae) inferred from molecular and morphological data
Authors: Gustafsson Claes , Persson Claes
Published: February 2007

Relationships among 38 taxa of Randia (Rubiaceae, Gardenieae) are estimated using nuclear ribosomal internal transcribed spacers (ITS), the 5S non‐transcribed spacer (5S‐NTS), and six morphological characters. In addition to Randia, 13 species from eight related genera in Gardenieae (four African, four neotropical) formed the ingroup. Three species from three more distantly related genera in Gardenieae (one African, two neotropical) were chosen as the outgroup. Representatives of the African ingroup genera Calochone, Macrosphyra, Oligocodon and Preussiodora formed a well supported monophyletic group as did the neotropical genera Rosenbergiodendron, Sphinctanthus and Tocoyena. Only when including morphological characters did Randia form a monophyletic group corresponding approximately to contemporary circumscription of the genus, but in this analysis Casasia appears sister to a group of Mexican, Central American, and Antillean Randia. There is no strong jackknife support, however, for either Randia or Casasia to be monophyletic. It is concluded that Randia is comprised of several distinct groups, each with its own geographical distribution. One group of Mexican, Central American, and Antillean Randia, including the type species, can be recognized as Randia in a strict sense. Two other South American groups can be recognized as separate taxa. One of these groups comprises mainly lowland species, and the second is comprised of strictly Andean species.
Classification of the North American species of Atriplex section Obione (Chenopodiaceae) based on numerical taxonomic analysis
Authors: Olvera Hilda Flores
Published: February 2007

North America is one of three main centers of species endemism for Atriplex, one of the largest genera in Chenopodiaceae. The monoecious herbaceous plants with Kranz anatomy, bibracteolate pistillate flowers lacking a perianth, cuneate to obovate fruiting bracteoles (usually broadest above the middle and connate at least to the middle), and erect seeds with superior radicles have been classified in Atriplex section Obione, which contains 32 species in North America. A numerical taxonomic analysis of the 32 species of the section, based on 30 morphological characters, was carried out to evaluate existing infra­sectional classifications. The phenetic analyses (cluster and ordination) suggest recognition of seven subsections, four of which are monotypic (Graciliflorae, Leucophyllae, Powellianae, and Truncatae). The largest group contains all species previously considered as the “pentandra group”, here recognized as subsection Arenariae. Another cluster includes A. cordulata, A. depressa, A. parishii, A. pusilla, A. tularensis, and A. wolfii, supporting the recognition of subsection Pusillae. Another cluster suggests recognition of subsection Argenteae, including A. argentea and A. saccaria, which where considered previosusly as monotypic subsections. Atriplex hillmanii is left as incertae sedis, its relationship with A. truncata needing further clarification.
A new interpretation of floral morphology in Garrya (Garryaceae)
Authors: Liston Aaron
Published: February 2007

Previous descriptions of Garrya (Garryaceae) floral morphology are inconsistent. Anatomical studies have long confirmed that the pistillate flowers possess an inferior ovary. Descriptions of the staminate flowers sometimes describe a vestigial superior ovary; other authors report no such structure. New observations of staminate flowers confirm the presence of an intrastaminal structure. I hypothesize that the structure previously interpreted as a vestigial ovary is, in fact, a vestigial nectary disc. Thus the staminate flowers cannot be considered hypogynous and do not contradict the interpretation of the pistillate flowers as epigynous. This observation resolves the paradox of contrasting floral form in the pistillate and staminate flowers.
Engendering Suspicion: Homosexual Panic in the Post-SovietDetektiv
Authors: Baer Brian James
Published: February 2007

This article examines the workings of the sexual closet within the enormously popular genre of the Russiandetektiv, or detective story. Informed by the work of Eve Kosofsky Sedgwick and D. A. Miller, the article focuses on the dramatization of homosexual panic among various male characters in Aleksandra Marinina'sStilist(1996) and Boris Akunin'sKoronatsiia(2001) in order to explore the experience of masculine subjectivity in post-Soviet culture. In both novels, a perceived crisis in patriarchal authority unleashes suspicions and anxieties regarding the experience of being and becoming a man, which is defined against the feminine and the homosexual. Figured both as an effect of and as a threat to male-male bonds, homosexual panic testifies to the interiorization of sexual and gender norms, which makes being male a highly self-conscious enterprise and fuels nostalgia for a mythic time before the appearance of homosexuality.
The Making of Monastic Demonology: Three Ascetic Teachers on Withdrawal and Resistance
Authors: Brakke David
Published: February 2007

Although in recent years fourth- and fifth-century Egyptian monasticism has received much scholarly attention of increasing methodological and theoretical sophistication, conflict with demons, a primary metaphor for the ascetic life in the literature of the period, has been left relatively unexplored. One reason for this lack of attention is a shift in the intellectual paradigms through which scholars approach ascetic literature: as they have moved from psychological and theological models to social and performative ones in interpreting ascetic theory and practice, seemingly subjective or theological themes such as demonological theory have given way to more cultural topics, such as constructions of the body and formations of ascetic institutions and practices, with their accompanying politics. But the neglect of demons is a function also of the weighty influence exercised by two fourth-century demonologists, Athanasius of Alexandria and Evagrius of Pontus, and of the powerful modern explications of monastic demonology based on these important sources. Together theLife of Antonyand the works of Evagrius construct, it seems,themonastic demonology, upon which later sources only elaborate.
From the “Land of Diverse Sects” to National Religion: Converts to Catholicism and Reformed Franciscans in Early Modern Poland
Authors: Kowalski Waldemar
Published: February 2007

Religious conversion is undoubtedly one of the most-explored aspects of medieval and early modern social history. Thefact that the literature concerning that problem is still significantly on the increase proves its scholarly importance. The subject has found a permanent place among works dealing with denominational relations in pre-partition Poland, and the list of such works is substantial. Theyshow a significant number of dispersed pieces of information con-cerning reconversions to the Catholic Church, with no lack of more general observations on this matter.
The Regaining of Faith: Reconversions among Popular Radicals in Mid-Victorian England
Authors: Larsen Timothy
Published: February 2007

There is a wealth of literature on Victorian religious doubt, and much of it is structured by implicitly defining pure faith in the context of nineteenth-century England as an organized, traditional, orthodox, trinitarian, and supernatural version of Christianity and then herding together people who deviate from this ideal at various points into vague categories such as “unbelief,” “infidelity,” “irreligion,” “honest doubt,” or “freethought.” Members of the numerically impressive group which is thereby constructed are then said to represent a strong trend that is given labels such as “the Victorian crisis of faith,” “the loss of faith,” or “secularization.” Much of this historiography is imbued with a Whig interpretation: these figures are seen as part of an inevitable movement toward the abandonment of religious beliefs by thinking people in the modern age as they progressed toward a more credible worldview. Indeed, the considerable attention that is paid to such people in the literature despite the fact that the Victorian age is often simultaneously declared to have been an extraordinarily religious one seems to be tacitly justified on the grounds that, although these figures may have been out of step with thespiritual confidence of their own generation, they were in step with the march of truth. The rhetoric of “honest doubt” is often tinged with the notion that a full appreciation of the fruits of modern thought and scientific inquiry would almost automatically lead to the abandonment of religious views; it is not just “honest” in the senseof candidly avowed and not derived from unworthy motives, but, rather, it is as if an “honest” examination ofthe facts could lead only to religious doubt. A contention of this study is that these interpretative tendencies have obscured a notable and telling countervailing pattern.
Two Centuries of Christianity in America:An Overview
Authors: Boyer Paul
Published: February 2007

While the year 2000 did not prove to be the eschatological blockbuster that some of our bolder Bible prophecy popularizers anticipated, nor the year when all our computers melted down, as some Y2K alarmists predicted, it did provoke some historians to step back from their usual topics of inquiry to attempt to sum up in a broad overview fashion some of the major developments in the century just past. A spate of books like Harvard Sitkoff's edited collection of essays,Perspectives on Modern America, with its subtitle, “Making Sense of the Twentieth Century,” were the result. In that spirit, as 2000 approached, I undertook an even more presumptuous venture: a brief overview of not one but two centuries of Christianity in America, from 1800 to the present, as a kind of outline sketch for a hypothetical book on the subject. The result is this essay. Once I had embarked on such a potentially foolhardy project, the practical question remained: What meaningful generalizations about two centuries of American Christianity could one offer in a relatively short space such as that provided by Church History's “Perspectives” feature? Still, Cotton Mather once boasted that he had boiled down the entire plan of salvation onto a single piece of paper, so from that perspective, five thousand or so words seemed ample indeed.