Special features of <i>Salvinia natans</i> (l.) All. reproduction
The process of Salvinia natans reproduction in Astrakhan region and Serpukhov district of Moscow region is studied. Mixed amphisporangiate soruses containing both mega and microsporangia ripening out of step by spring are discopvered. Of all soruses one is usually mega, and others are micro. Megasoruses contain from 15 to 30 megasporangia with white coloring. There are from 2 to 22 microsoruses in the nod, and there are several hundreds of microsporangia in each microsorus. It was noted that a strong movement of water contributes to early death of the old sections of Salvinia shoots and to breakage of young stems in metamers that spread out in all directions providing vegetative reproduction and dispersal of species. Thus, Salvinia natans identified reproductive r-strategy, carried out in two tactics: spore mass reproduction occurring primarily in late spring and in sync quickly and vegetative reproduction sporophytes, extended in time from mid-summer to late autumn. The first tactic is used to restore the population after the winter period, the second - to hold and capture the space and type of settlement.