ABSTRACT:

Pinellia species possess a long, slender spadix appendix that extends well beyond the spathe. We assessed the function of the spadix appendix in the green dragon, Pinellia pedatisecta. Plants were subjected to one of the following four experimental treatments: removal of the spadix appendix, removal of the male flowers, removal of the spadix and male flowers, and sham control. Fruit set was reduced in plants lacking male flowers, but the degree of reduction was greater in plants that also lacked the spadix appendix than in those that possessed it. The reduction in fruit set that accompanied male flower removal is consistent with the established ability of this species to self-fertilize. Our finding that the reduction of fruit set was less when the spadix appendix was present than when it was absent suggests that the appendix attracts pollinators and promotes crossfertilization. Crossing would help maintain genetic diversity in this species that also selfs.