Using size-class structure to monitor growth of underdeveloped embryos in seeds of three Aristolochia species: implications for seed ecology

Size-class structure was used to monitor the growth of underdeveloped embryos in two seed cohorts of Aristolochia macrophylla, A. tomentosa and A. californica and the results are related briefly to differences in seed dormancy among and within the three species. The size-class method of presenting embryo growth data allows more insight to be gained into the embryo-level cause(s) of seed dormancy than does the cumulative growth curve. This appears to be the first report on use of size-class structure to monitor growth of underdeveloped embryos.