Structural Features Underlying Hardseededness in Geraniaceae

Abstract: The proportion of hard Geraniaceae seeds ranges from 0 to 100%, depending on species. By analysing the characteristics of hardseededness through the pathway of water uptake in soft seeds provided localization of the chalazal area in water uptake. This represents the most important feature of seed coat permeability. The structural difference between hard-and softseededness was clarified by comparing different species with exclusively permeable or impermeable seeds. Soft seeds form a wide opening at the chalazal slit, while hard ones close the slit using adjacent palisade cells so effectively continuing the impermeable barrier.