While there is abundant evidence to suggest that pollinators influence the evolution of plant floral traits, there is little direct evidence that interactions between plant species shape the evolution of such characteristics. The purpose of this study was to determine whether the presence of the morning glory Ipomoea purpurea alters patterns of selection on floral traits of its congener, Ipomoe...

Three new immigrant species of Spilanthes Jacq. (Asteraceae) is described for the first time from India. Their current nomenclature and an artificial key for the identification of the 5 Indian species are provided. The identity of the commonly used 'tooth-ache' plant is also discussed.

(1) Ipomoea hederacea, a common weed in cultivated fields of eastern North America, disappears quickly following abandonment of farming. (2) The effects of competition and nitrogen addition on the growth and reproduction of I . hederacea were studied during the first year of abandonment. (3) Competition and fertilization had significant absolute effects on almost all biomass variables measured ...

Although Japanese morning glory (Ipomoea nil (L.) Roth.) has been used intensively for genetic studies, DNA markers have not been developed in Ipomoea nil sufficient to cover all chromosomes. Therefore, we conducted microsatellite (simple sequence repeats, SSR) marker development in I. nil for future genetic studies. From 92,662 expressed sequence tag (EST) sequences, 514 unique microsatellite-...

Two greenhouse studies were conducted to investigate the variability in tolerance to a sublethal dose of glyphosate among accessions of pitted morningglory, hybrid morningglory (a fertile hybrid between pitted and sharppod morningglory), and sharppod morningglory, collected from several states in the southern United States. The first study was conducted to evaluate the variability in tolerance ...

Leaf shape is a highly variable phenotype, and is likely influenced by many sources of selection. Ipomoea hederacea exhibits an adaptive latitudinal cline in leaf shape, which is controlled by a single Mendelian locus: lobed individuals dominate the north with entire-shaped individuals mostly in the south. We test if the following candidate selective agents, suggested by the literature, are res...

Leaf shape is one of the most variable plant traits. Previous work has provided much indirect evidence that leaf-shape variation is adaptive and that leaf shape influences thermoregulation, water balance, and resistance to natural enemies. Nevertheless, there is little direct evidence that leaf shape actually affects plant fitness. In this study, we first demonstrate that populations of the ivy...

A cytotaxonomic survey has been carried out on 87 species and 11 subspecies of Eriospermum (Eriospermaceae). The results show that the basic haploid number varies from x=5 to x=10 and that, according to karyotype, the species can be subdivided into eight distinct Groups. The larger number of species belong to Group A with 62 taxa. Group E karyotype, found in nine species, is bimodal and include...

Although recent evidence indicates that coevolutionary interactions between species often vary on a biogeographical scale, little consideration has been given to the processes responsible for producing this pattern. One potential explanation is that changes in the community composition alter the coevolutionary interactions between species, but little evidence exists regarding the occurrence of ...