Hardseededness development and its breakdown of Lotononis bainesii grown with Digitaria decumbens, at Mt. Cotton, southeast Queensland in Australia, were investigated. Strong hierarchical development of hardseededness took place within the next 6 days following the apparent cessation of embryo development, where germination and hardseededness of collected seeds were negatively correlated with each other with time. The further hardseededness development in standing plants was observed and this inherent attribute of hardseededness development was considered as one of the constraints for the plant replacement through the seedling recruitment, since the natural release of germination was found not reliable even with a high density of soil seed bank. The controlled fire contributed hardseededness breakdown but also killed the associated grass and a considerable proportion of soil seed reserves, depending on the intensity of the fire and the soil seed distribution, which affect replacement of plants.