Constraints on Seed Production and Storage in a Root-Suckering Banksia

(1) This study aimed to quantify all possible constraints on seed and fruit availability in a woody perennial, Banksia elegans. Over 90% of post-fire resprouts and root suckers in the study population did not produce any seeds during the ensuing sixteen years. (2) All ramets flowered profusely in their sixteenth year. Damage to reproductive parts by insect larvae and granivorous birds was negligible. (3) B. elegans appears to be essentially outbreeding. The efficiency of pollinators, mainly nectarivorous birds, was hampered by lack of anther dehiscence in the sterile plants, and clonal nature of the population. (4) Most stigmas received no germinable pollen and almost all fertilized ovules did not develop further. (5) Shortage of mineral nutrients, especially nitrogen and phosphorus, appeared to account for the variations in follicle production and high level of seed abortion. (6) Viability of intact seed was very low. Only 0 0002% of ovules in the current crop contributed to the viable seed bank one year after anthesis. Root suckering appears to function as a nutrient-conserving alternative to sexual reproduction in this species.