Inconsistent expression of the gigas effect in polyploid Oxalis.

Premise: It is well-known that whole genome duplication (WGD) has played a significant role in the evolution of plants. The best-known phenotypic effect of WGD is the gigas effect, or the enlargement of polyploid plant traits. WGD is often linked with increased weediness, which could be a result of fitness advantages conferred by the gigas effect.