Architectural constraints male fertility variation and biased floral morph ratios in tristylous populations

摘要

The arrangement of sex organs (styles and stamens) in the floral morphs of tristylous Pontederia parviflora. L, M, S refer to the long-, mid, and short-styled morphs and arrows are the compatible pollinations. Mean pollen production values for each stamen level are indicated based on our measurements. Note the large difference in pollen production between mid-levels anthers of the L- and S-morphs