Structural features underlying hardseededness in Geraniaceae

The proportion of hard Geraniaceae seeds ranges from 0 to 100%, depending o n species. By analysing the characteristics of hardseededness through the p athway of water uptake in soft seeds provided localization of the chalazal area in water uptake. This represents the most important feature of seed co at 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, wh ile hard ones close the slit using adjacent palisade cells so effectively c ontinuing the impermeable barrier.