Pollen morphology and variability of native and alien, including invasive, species of the genus Spiraea L. (Rosaceae) in Poland.

The pollen morphology was studied in 25 taxa of the genus Spiraea L. The aims of this study were to describe the pollen morphology and variability and to determine whether the pollen features of alien, expansive or invasive Spiraea species differ from those of other taxa. The species of Spiraea were analysed for nine quantitative pollen traits as well as the following qualitative traits: the outline, shape and exine ornamentation. In total, 750 pollen grains were measured. Based on the pollen key exine ornamentation features, then individual Spiraea species were distinguished, while the other species formed groups of usually 2-3, up to 8 species. The most important pollen features included length, width and course of grooves and striae, presence or absence of perforations, as well as their number and diameter. The most variable taxa for all the nine biometric traits jointly were S. ×billardii, S. veitchii, S. nipponica and S. cana. The pollen of the invasive S. tomentosa differed from the other taxa studied, unlike the other invasive species (S. douglasii and S. japonica).

Nutlets of Tilia cordata Mill. and Tilia platyphyllos Scop. - Source of bioactive compounds.

The aim of this study was to analyse contents of phytosterols, carotenoids, tocochromanols and fatty acid composition in oil from nutlets of linden. Standard determination methods for these compounds were applied using liquid and gas chromatography. In the analysed oils from small and large-leaved lime the dominant acids included linoleic (53.1 and 54.1%), oleic (18.5 and 22.2%), palmitic (15.3 and 11.8%). Linden seed oil was characterised by very high contents of phytosterols (2-2.5 g/100 g). ß-Sitosterol was the dominant phytosterol (80-83%). Additionally squalene was detected at 806 and 607 mg/100 g, respectively, for Tilia cordata and T.platyphyllos. It was found that linden seed oil contains tocopherols (93%) and tocotrienols (7%). In terms of tocochromanol contents this oil is surpassed only by wheat germ oil. In terms of the α-T equivalent these oils contain 95 (Tilia cordata) and 50.6 mg/100 g vitamin E (Tilia platyphyllos).