Development is remarkably reproducible, producing organs with the same size, shape, and function repeatedly from individual to individual. Yet, these reproducible organs are composed of highly variable cells. My laboratory focuses on the mechanisms that produce diversity in cell size in the Arabiodpsis sepal and the mechanisms that ensure uniformly sized sepals are produced from these variably sized cells. We find that the plant utilizes apparently stochastic fluctuations of a the ATML1 transcription factor to initiate the differentiation of different cell types (giant cells scattered among small cells). In other cases, the plant essentially ignores cellular variability by averaging it out over space and time to arrive at reproducible sepal size and shape.