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This research paper presents findings of an investigation about antibacterial effect of methanol/water fractions as well as cytotoxic activity of the extracts obtained from Pedicularis wilhelmsiana (Scrophulariaceae) which grows in Azarbaijan/Iran by agar well diffusion method and brine shrimp lethality test successively. Phytochemical study of this plant was determined as well. A combination of solid-phase extraction (SPE), preparative reversed-phase HPLC analysis and spectroscopic means were applied for fractionation, purification, and identification of ingredients respectively. Antimicrobial test demonstrated that 40% and 60% methanol/water fractions were more active than methanolic extract and other SPE fractions. No cytotoxic effect was detected from the extracts of this plant by brine shrimp lethality assay. Phytochemical study of aerial parts of Pedicularis wilhelmsiana (P. wilhelmsiana) afforded two phenylethanoids (verbascoside and martynoside), three iridoids (Aucubin, ipolamiid, 5-hydroxy-8-epi-loganin) and two flavonoids (luteolin, luteolin-7-glucoside) along with mannitol on the basis of spectral evidences (UV, ¹H and 13CNMR) as well as comparison with literature data. The findings of this research supported further studies related to antibiotic potential of methanolic extract of P. wilhelmsiana. [ABSTRACT FROM AUTHOR]

Question Hemiparasitic plants can profoundly affect the structure of the community in which they occur, mainly due to parasitic suppression of hosts. As a consequence, non-host species have the opportunity to colonize resulting gaps. In contrast to most grassland species, hemiparasites are generally short-lived and can reach high densities; as a consequence, vegetation gaps are left after their death. These gaps form microsites more suitable for seed germination and therefore might increase recruitment of other species. Which species suffer or profit from parasitism and is there a positive effect on seedling establishment? Location Semi-natural grasslands in northern Belgium. Methods We selected two hemiparasitic plant species from contrasting vegetation types: Rhinanthus angustifolius growing in mesotrophic grassland and Pedicularis sylvatica growing in oligotrophic heath-grassland. A weeding experiment was set up at six sites in which the hemiparasite was repeatedly removed in half of the plots during three growing seasons. The abundance change of individual species was compared between weeded and control plots. After the second growing season, seeds of up to ten species were added. The number of seedlings in the third year was then compared between weeded and control plots. Results Rhinanthus removal significantly affected the abundance of species relative to control plots, both positively and negatively, and decreased the species evenness. Pedicularis removal only increased the abundance of some species. Only Juncaceae (but no other graminoid families) increased after Rhinanthus and Pedicularis weeding, and there was considerable variation within functional groups. Moreover, based on our observations, we propose as a new hypothesis that species with persistent clonal spread are more vulnerable to parasitism. Once attached, resources are potentially drawn from a whole network of interconnected ramets. Finally, only half of the sown species successfully established seedlings; hemiparasite removal had a significantly negative effect on seedling number for two of these species. Conclusions Effects of hemiparasites on species differ considerably, also within functional groups. Persistent clonal spread emerges as an important plant trait determining vulnerability to hemiparasites. Finally, our results suggest that hemiparasitic plants might have a limited positive effect on seedling establishment in these semi-natural grasslands where chances for successful establishment were shown to be low. [ABSTRACT FROM AUTHOR]

Highlights: [•] The first study of arctic species of Pedicularis in a molecular phylogenetic context. [•] Arctic Pedicularis evolved 12–14 times independently. [•] Most arctic Pedicularis have high mountain origin. [•] The arctic taxa show considerable niche conservatism with respect to soil moisture. [•] Morphological traits of arctic Pedicularis show a non-uniform pattern of evolution. [ABSTRACT FROM AUTHOR]

Aims: Hemiparasitic plants often produce nutrient-rich litter with high decomposition rates, and thus can enhance nutrient availability. When plant species have differential affinities for this nutrient source, hemiparasitic litter might influence species composition in addition to the parasitic suppression of host species. We expected that species adapted to fertile habitats derive a higher proportion of nutrients from the hemiparasitic litter compared to other species. Methods: N-labeled litter of Rhinanthus angustifolius and Pedicularis sylvatica was added to experimental field plots and adjacent litter bags. We examined N release from the litter, N uptake by the vegetation 2, 4 and 12 months after litter addition and differences in the proportion of N taken up from the litter (N) between co-occurring species. Results: The percentage of N in shoots of co-occurring plant species that is derived from the added hemiparasitic litter (N) strongly differed between the species (0.1-6.2 %). After exclusion of species with an alternative N source (legumes as well as ectomycorrhizal and ericoid mycorrhizal species), N was positively related ( p < 0.001) with specific leaf area (SLA) and at Pedicularis sites with leaf N concentration (LNC) and leaf phosphorus concentration (LPC) ( p < 0.05), i.e. leaf traits associated with a fast-growth strategy and adaptation to high-nutrient environments. Conclusions: Our results suggest that nutrient release from hemiparasitic litter favors plant species with a fast-growth strategy adapted to high-nutrient environments compared to species with a slow-growth strategy. Whether continued hemiparasitic litter inputs are able to change species composition in the long term requires further research. [ABSTRACT FROM AUTHOR]

Hemiparasitic plants can substantially change plant community structure; the drainage of host resources has a direct negative effect on host biomass and, as a consequence, promotes non-host biomass production (parasitism pathway); on the other hand, hemiparasitic litter inputs can enhance nutrient cycling which may have an indirect positive effect on both host and non-host biomass production (litter pathway). We evaluated the net effect of both pathways on total shoot biomass (with and without the hemiparasite) and shoot biomass of graminoids, forbs and ericaceous shrubs using a removal experiment in three sites infested with the annual Rhinanthus angustifolius, and three sites infested with the biennial Pedicularis sylvatica. We addressed the potential importance of litter effects by determination of litter quantity and quality, as well as modeling N release during decomposition. In the second year after removing the hemiparasites, total plant biomass at Rhinanthus sites was 24 % higher in weeded plots than in control plots, while weeding had no significant effect at Pedicularis sites. The increase in total biomass following Rhinanthus removal was mainly due to a higher biomass of graminoids. The amount of litter produced by Rhinanthus was only half of that produced by Pedicularis; N contents were similar. The amount of N in the litter was 9 and 30 % of the amount removed by mowing for Rhinanthus and Pedicularis sites, respectively. Within 2 months, about 45 % of the N in both hemiparasitic litter types was released by decomposition. Our results suggest that in addition to the suppression of host biomass due to parasitism, positive litter feedbacks on host and non-host biomass-via an increase in nutrient availability-also affect plant community structure. We propose that, depending on the particular hemiparasite and/or site conditions, these positive litter feedbacks on shoot biomass can compensate for the negative effect of parasitism. [ABSTRACT FROM AUTHOR]

Pedicularioside G is a new compound of phenylpropanoid glycosides, isolated from Pedicularis striata in our laboratory. Pedicularioside G inhibited two major angiogenic responses, human umbilical vein endothelial cell proliferation and migration, as well as neovascularization in a chicken embryo chorioallantoic membrane model. In addition, pedicularioside G inhibited human hepatoma cells proliferation and migration in vitro along with transplanting tumour formation and growth in a chicken embryo chorioallantoic membrane model. So pedicularioside G has anti-angiogenic, antitumour growth, antimetastatic and antitumoural effects. Pedicularioside G also remarkably reduced reactive oxygen species level in both vein endothelial cells and hepatoma cells in a concentration-dependent manner. These results suggest that the anti-angiogenic and antitumoural effects of pedicularioside G might partially attribute to its antioxidative activity. [ABSTRACT FROM AUTHOR]

In 1998–2001, I studied disturbance effects on the population structure and dynamics of a grassland strict biennial Pedicularis sylvatica, and on the species demography (monthly dynamics of seedling recruitment in 1998 and within- and between-year survival in 1998–2000). In two Czech populations, I established three experimental disturbance regimes: (1) a gap treatment, that simulated grazing by clipping vegetation and creating small gaps, (2) a mowing treatment, where I clipped the vegetation, and (3) a no management treatment, where I left the vegetation untreated. The number of recruiting seedlings varied greatly by year, and demographic structure of populations showed significant year-to-year oscillations in mean seedling numbers, from low (3 ± 0.7 s.e. per 0.25 m2 plot) to high (103 ± 20). Inversely in the same years and plots, mean adult numbers in populations oscillated from high (12 ± 2) to low (0.7 ± 0.3). Disturbance effects were only important for seedling recruitment in early census dates in all years. In 1998, most seedlings recruited in April–May in gaps in both sites, but most died before winter. Within- and between-year survival was not affected by disturbance regimes but fluctuated significantly among years. Between-year survival increased with increasing size of the overwintering bud and was higher in disturbance treatments. Since the oscillations in population structure did not significantly vary in response to experimental disturbances, population dynamics may be driven endogenously rather than by disturbance events. The weak disturbance effects on species demography may also indicate population resilience to changes in habitat quality. However, since disturbances promoted seedling recruitment, grazing or mowing regimes are strongly recommended, as they create regeneration opportunities and maintain habitat quality, meeting the species long-term conservation goals. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the nature and status of vegetation in Woodwalton and Holme fens in Huntingdonshire, England. Information is presented on topography and drainage at Woodwalton fen. It has found that there has been some development of acid bog in Woodwalton fen based on evidence available from peat stratigraphy and from historical documents. It relates the complete absence of rare fen species at Woodwalton. Some species like Pedicularis sylvatica and Carex echinata have reached the verge of extinction due to considerable drying out.