XVI International Botanical Congess
The structural features of the mature adventitious root cortex and apoplastic permeability have been determined for two wetland plants of differing habitats: Nymphaea odorata and Caltha palustris. At maturity, N. odorata roots have an endodermis with Casparian bands, an extensive aerenchyma with hexagonal lacunae and astrosclereids, and a hypodermis with its uniseriate exodermis with Casparian bands and suberin lamellae. The roots of C. palustris have an endodermis with Casparian bands, a non-aerenchymatous cortex except in old roots where schizogenous lacunae may appear, and a uniseriate exodermis with Casparian bands and suberin lamellae. In old roots, the movement of dyes into the cortex was blocked at the outer edges of the exodermis.