Reproductive Effort of Two Perennial Weed Species in Different Habitats

SUMMARY (1) The reproductive efforts of Rumex crispus L. and Rumex obtusifolius L., two perennial, iteroparous weeds with delayed reproduction, were studied in different habitats. The probability of flowering in R. crispus was correlated with rosette diameter the previous autumn. (2) For both species, above ground dry weight per plant and reproductive effort differed significantly between habitats. Reproductive effort, based upon aboveground dry weight, varied between 042 and 0.61 for R. crispus, and between 0.26 and 0.59 for R. obtusifolius. (3) A simple allometric relationship between above-ground dry weight and fruit weight per plant holds for both species. (4) A large portion of the reproductive effort was devoted to ancillary reproductive