A b s t r a c tThe significance of root colonization by mycorrhizal fungi for the growth and development of Helichrysum arenarium was investigated in two independent experiments. In the first experiment the association of root colonization level with the pluviothermal conditions within the growing season and the age of a natural plant population was analyzed. In the second one, under controlled conditions, the influence of artificial inoculation with the arbuscular fungus Glomus intraradices on the features of plants raised from achenes was studied. It was shown that hydrothermal conditions during blooming period had a greater influence on reproduction processes of sandy everlasting than both the population age (the secondary succession progress) and the level of root colonization by mycorrhizal fungi. High amount of precipitation at plant generative development phase positively influences the potential and actual fertility of ramets. The presence of arbuscular fungus in the soil favors the growth and development of sandy everlasting specimens at their early growing stages: they have a better-developed root system and a greater photosynthetic area.

Summary Introduction: The high concentration of some trace elements in medicinal plants may lowering the value of herbal material, and may cause poisoning effects. Objective: The aim of this research was to evaluate the content of trace elements in the organs of: sandy everlasting, yarrow and stinging nettle. Methods: In the soil samples, the grain size composition, pH, the content of carbon and nitrogen were determined. In the plant material and for the soil samples, the total contents of Zn, Cu, Mn, Fe, Pb were assayed. The values of the bioconcentration factor and translocation factor were also calculated. Results: The concentration of metals in plant tissues followed in order: Fe>Mn>Zn>Pb>Cu>Hg. The studied species of medicinal plants accumulated mainly Zn, Pb and Hg. It was also shown a high Hg mobility and a low Pb mobility which mainly accumulated in the roots. Conclusions: As our research shows the plants used in phytotherapy, should come from plantations monitored for toxic heavy metals in soil.

The aim of the research has been to assay the contents of Zn, Cu, Mn, Fe, and Pb in soil and in the organs of wild Thymus serpyllum L. acquired from three natural habitats from the Kuyavia-Pomerania Province (Poland) not exposed to contamination with metals. As compared with the contents of the geochemical background of the soils in the region and the value of enrichment factor (EF), there was noted a considerable content of Pb in the soil from two locations. The Pb content in plant tissues in one of the three locations was higher than the admissible content specified by the World Health Organization WHO (above 10 mg kg−1 d.w.). As for the Zn content, only the plants from the locations with the relatively youngest phytocenosis met the conditions for herbs to be used for phytotherapy. The Zn content in the dry weight of the plants collected from the other two locations exceeded 50 mg kg−1. The risk of an elevated content of Zn and Pb in the plants makes it necessary to monitor the soil environment and to limit the collection of the plants from natural habitats, as well as to encourage the collection from controlled habitats.

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