Untying the True Lover´s knot: Negligible cost of reproduction in Paris quadrifolia L.

By a simple experiment we investigated whether negative consequences of one cancelled reproductive event may be noted during the following three seasons in a long-lived perennial understory herb True Lovers Knot (Paris quadrifolia) growing in a relatively stable environment. In measuring the size of the growing rhizome (length and biomass), the height of the aboveground shoots and the size of reproduction (number of seeds) in three groups of individuals (1/3 flowering, 1/3 flowering but decapitated at the budding stage in the first year of the experiment and 1/3 non-flowering) we were able to detect only a minor positive effect of the intervention on flowering frequency, an insignificant difference in shoot length, an inverse relation in seed production, and again an almost undetectable increase in rhizome growth. Instead large plants remained large and small stayed small through the full three years of the experiment. We thus conclude that P. quadrifolia-individuals may or may not flower without significantly affecting their long-term success.