| The Anatomical Basis for Hygroscopic Movement in Primary Rays of Daucus Carota Ssp. Carota (Apiaceae)
||Polarization microscopy was used to examine the cause of hygroscopic movement in umbellet pe- duncles, or primary rays, of Daucus carota (Apiaceae). Net microfibril orientation of thick-walled parenchyma cells is perpendicular to the long axis of the...
|Carbon Integration in Plantago Aristata (Plantaginaceae): The Reproductive Effects of Defoliation
||Patterns of carbon integration in aclonal species are poorly understood in spite of their potential to influence individual fitness. To provide more information about these patterns, we performed a defoliation experiment with P. aristata. We examined...
|Carbon Integration in Two Plantago Species
||We measured the pattern of export of 14C-assimilate from reproductive spikes and leaves subtending spikes in Plantago aristata and P. virginica. In P. aristata, little 14carbon was exported to any other reproductive metamer (lea...
|A Comparison of Germination and Early Growth of Four Early Successional Tree Species of the Southeastern United States in Different Soil and Water Regimes
||To learn more about the basic biology of exotic relative to native tree species we conducted a greenhouse experiment comparing the germination and early seedling growth of four early successional tree species found in the southeastern United States: ...
|Demographic constraints in three populations of Lobelia boykinii: a rare wetland endemic
||Knowledge about the factors restricting reproduction in many rare wetland plant species is limited. One such species is Lobelia boykinii. We conducted a study of L. boykinii to determine which factors most influence its reproductive success. We exami...
|Effect of parental flowering and dispersal times on offspring fate in Daucus carota
||Seeds collected from parents that flowered at different times were dispersed onto experimental plots at different times during the normal dispersal season. Parental flowering and dispersal times, which are correlated with each other, independently af...
|Fitness Effects of Floral Plasticity and Thermoregulation in a Thermally Changing Environment
||To better understand the evolution of phenotypic plasticity and thermoregulation and their potential value for ectotherms in the face of global warming, we conducted field experiments to measure their effects on fitness and their association with rep...
|Floral Reflectance, Color, and Thermoregulation: What Really Explains Geographic Variation in Thermal Acclimation Ability of Ectotherms?
||Adaptive phenotypic plasticity in thermally sensitive
traits, that is, thermal acclimation, generally increases with increasing
latitude and altitude. The presumed explanation is that high-latitude/
altitude organisms have evolved greater acclimat...
|The genetic and environmental control of reproductive timing in a short-lived monocarpic species Daucus carota (Umbelliferae)
||(1) Offspring of annual, biennial and triennial Daucus carota were grown under three nutrient regimes in a growth chamber to measure the effects of nutrient supply and maternal age of flowering on offspring size and growth rate and the effects of all...
|The influence of hygroscopic movement on seed dispersal in Daucus carota (Apiaceae)
||The influence of hygroscopic movement on seed dispersal in Daucus carota was examined. When relative humidity increases, umbels containing mature fruits close; when relative humidity drops, umbels open. Tests of the effectiveness of small-and large-a...
|Latitudinal variation in reproductive timing of a short-lived monocarpic, Daucus carota: (Apiaceae)
||A reciprocal transplant experiment was conducted to examine several aspects of life-history variation in Daucus carota along its latitudinal range in eastern North America. Seeds collected from natural populations at 36°, 42°, and 45° N were sown ont...
|Multigenerational effects of flowering and fruiting phenology in Plantago lanceolata
||Phenological patterns of flowering and fruiting can be influenced by the effects of reproductive time on seed production. We propose here that these patterns are also influenced by phenological effects on offspring quality. Furthermore, we hypothesiz...
|Onset of reproduction in plants: size-versus age-dependency
||Understanding the roles of age and size in the timing of first reproduction or flowering in plants has become a goal for those investigating the evolution of life cycle patterns in general. Here I review the studies that are helping to clarify these ...
|Parental effects in Plantago lanceolata. L. I. A growth chamber experiment to examine pre-and post-zygotic temperature effects
||In spite of the potential evolutionary importance of parental effects, many aspects of these effects remain inadequately explained. This paper explores both their causes and potential consequences for the evolution of life-history traits in plants. I...
|Parental effects in Plantago lanceolata. L. III. Measuring parental temperature effects in the field
||To determine the evolutionary importance of parental environmental effects in natural populations, we must begin to measure the magnitude of these effects in the field. For this reason, we conducted a combined growth chamber–field experiment to measu...
|Parental effects in Plantago lanceolata L. II. Manipulation of grandparental temperature and parental flowering time
||In an experimental study of Plantar lanceolata L., postzygotic environmentally induced parental effects were (1) transmitted across generations, (2) genotype-specific, and (3) mediated by natural differences in flowering phenolop. Individuals were cl...
| Parental Effects on Seed Mass: Seed Coat but Not Embryo/Endosperm Effects
||Many biologists studying environmentally induced parental effects have indirectly suggested that the parental environment
alters seed mass by altering the amount of endosperm or embryo tissue in the seed. We tested this hypothesis by measuring
|Phenological patterns of terrestrial plants
||The term phenology is derived from the Greek word phaino meaning to show or to appear. Hence, phenology is defined as the study of the seasonal timing of life cycle events. For plants the seasonal timing of such events can be critical to survi...
|PHENOTYPIC PLASTICITY, PARENTAL EFFECTS, AND PARENTAL CARE IN PLANTS: AN EXAMINATION OF SPIKE REFLECTANCE IN PLANTAGO LANCEOLATA (PLANTAGINACEAE)
||We explore the relationships among phenotypic plasticity, parental effects, and parental care in plants by presenting data from four
experiments examining reflectance/color patterns in Plantago lanceolata. In three experiments, we measured spike (in...
|The Role of Population Dynamic Models in Biogeographic Studies: An Illustration from a Study of Lobelia boykiinii, a Rare Species Endemic to the Carolina Bays
||Here we submit that mathematical tools used in population viability analysis can be used in conjunction with floristic and faunistic surveys to predict changes in biogeographic range. We illustrate our point by summarizing the results of a demographi...
|Seed Dispersal in Wild Carrot (Daucus Carota)
||While animals and wind have been proposed as agents of seed dispersal for Daucus
carota, a common weed, no quantitative data can be found in the literature to support
either. This paper presents evidence to support both modes of dispersal. S...
|Seed Mortality in Daucus Carota Populations: Latitudinal Effects
||Daucus carota, a common herbaceous weed, grows over a wide latitudinal range in eastern North America. Viability and germination tests of mature seeds collected from 36° to 45°N were conducted to measure predispersal seed mortality. Viability ...
|Sexual Dimorphism in a Temperate Dioecious Tree, Ilex montana (Aquifoliaceae)
||A study of a population of Ilex montana mountain winterberry showed a strongly skewed age distribution with few individuals reaching reproductive maturity. Sexual differences of the reproductive adults were manifested in several ways. The tert...
|Temperature-sensitive alternative oxidase protein content and its relationship to floral reflectance in natural Plantago lanceolata populations
||In many plant species, the alternative respiratory pathway consisting of alternative oxidase (AOX) is affected by growth temperature. The adaptive significance of this temperature-sensitivity is unresolved.
Here, leaf and spike (flower cluster) AOX...
|Temperature-sensitive anthocyanin production in flowers of Plantago lanceolata
||Flower color in the weedy perennial Plantago lanceolata is phenotypically plastic. Darker flowers are produced at cooler ambient temperatures, and circumstantial evidence suggests that this is adaptive. The goal of this project was to investigate the...
|Timing of seed dispersal in Daucus carota L. (Apiaceae)
||This study describes the temporal pattern of seed dispersal in Daucus carota and examines the fate of seeds dispersed at different dates in SE Michigan. Plants varied greatly in both time of onset and rate of dispersal. Onset was directly related to ...
| Variance Models in the Study of Life Histories
||Gillespie (1974) demonstrated mathematically that reducing the variance in offspring number could increase a genotype's fitness above that of another genotype having the same mean reproductive output. The implication was that natural selection could ...
|What Is an Adaptive Environmentally Induced Parental Effect?
||Biologists working in fields as diverse as mammalian behavior, plant ecology, microbial genetics, quantitative genetics, and insect ecology have shown that environmentally induced parental effects can be found in most kingdoms of living organisms. Su...