To resist establishment by an invasive plant, a community may require one or more species functionally similar to the invader in their resource acquisition pattern. In this study, communities consisting of native winter annual forbs, non-native annual grasses, native perennials, or a combination of the two native communities were established with and without Centaurea solstitialis to determine ...

BACKGROUND AND AIMS The Mediterranean region is of prime importance to biodiversity at a global level, mainly due to the abundance of endemic plant species. However, information about these species is still scarce, especially at the genetic level. In this paper the first assessment is reported of the genetic structure of Centaurea horrida (Asteraceae), an endemic, sea-cliff-dwelling plant from ...

Interest to natural medicines is increased for the sake of fewer side effects, microbial resistence and more compatibility to the human body. Centaurea depressa (commonly known "cornflower") belongs to compositeae family, which comprises more than 74 species in Iran. It has been claimed that it can be used in many cases, such as infections, cough, constipation, dermatitis, fever, jaundice, pain...

The genus Centaurea with an extensive background in Iranian traditional medicine represents more than 70 species in Iran that some of them are endemic to Iran. A variety of secondary metabolites has been isolated from this genus thus far. Sesquiterpene lactones and flavonoids have been reported as main compounds of C.bruguierana. Methanolic extract and different fractions of the whole fruiting ...

Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, re...

Global environmental changes are altering interactions among plant species, sometimes favoring invasive species. Here, we examine how a suite of five environmental factors, singly and in combination, can affect the success of a highly invasive plant. We introduced Centaurea solstitialis L. (yellow starthistle), which is considered by many to be California's most troublesome wildland weed, to gr...

In 2004, J.C. Tong found bounds for the approximation quality of a regular continued fraction convergent of a rational number, expressed in bounds for both the previous and next approximation. We sharpen his results with a geometric method and give both sharp upper and lower bounds. We also calculate the asymptotic frequency that these bounds occur.