We report the green synthesis of silver nanoparticles by using Euphorbia condylocarpa M. bieb root extract for the synthesis of N-monosubstituted ureas in water. UV-visible studies show the absorption band at 420 nm due to surface plasmon resonance (SPR) of the silver nanoparticles. This reveals the reduction of silver ions (Ag+) to silver (Ago) which indicates the formation of silver nanoparti...

The essential oils of branchlets and fruits of Juniperus excelsa subsp. excelsa and Juniperus excelsa subsp. polycarpos were examined for their antioxidant activity. The compositions of the essential oils were studied by GC and GC-MS. To evaluation the antioxidants activity of the volatile oils, pure components and positive controls at different concentrations, thin-layer chromatography (TLC) s...

Abundances and interactions among biological control insects and their effects on target invasive plants were monitored within the flower heads and roots of diffuse knapweed, Centaurea diffusa, and in spotted knapweed, Centaurea stoebe, along the Colorado Front Range. Flower weevils, (Larinus species) and root-feeders (Cyphocleonus achates and Sphenoptera jugoslavica) were released on knapweed ...

Crabs of the genus Plagusia Latreille, 1804 (Crustacea: Brachyura: Plagusiidae) are well known for their habit of clinging to driftwood or ship hulls and are therefore prone to trans-oceanic transport. One of the consequences of this large dispersal potential seems to be the circumtropical distribution of one species, Plagusia depressa (Fabricius, 1775). This species comprises two subspecies, t...

Plants of Juniperus communis L. var. communis, J. c. var. depressa Pursh, J. c. var. jackii Rehdr, J. c. var. saxatilis Pall. were sampled and SNPs from nrDNA were examined. Based on these data and previous data, a new variety of J. communis is recognized: Juniperus communis var. charlottensis R. P. Adams, var. nov. It occurs in muskeg bogs on Queen Charlotte Island, British Columbia and in the...

In a microcosm experiment, I tested how species composition, species richness, and community age affect the susceptibility of grassland communities to invasion by a noxious weed (Centaurea solstitialis L.). I also examined how these factors influenced Centaurea’s impact on the rest of the plant community. When grown in monoculture, eight species found in California’s grasslands differed widely ...

       From hexanic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four triterpenoids namely taraxasterol, y-taraxasterol, poriferasterol and b-sitosterol have been isolated by column chromatography, thin layer chromatography, and crystallization. Their structures were elucidated by spectroscopic methods (UV, IR, MS, 1H and 13C-N...