The Root Cortex of the Nymphaeaceae, Cabombaceae, and Nelumbonaceae

The roots of selected water lilies, Nymphaeaceae and Cabombaceae, and water lotuses, Nelumbonaceae, were examined using epifluorescence, brightfield, and modified darkfield microscopy to determine the characteristics of root cortical structure. The members of the Nymphaeaceae have an endodermis usually with Casparian bands only, many astrosclereids and some transverse diaphragms scattered throughout the aerenchyma, and a hypodermis with a uniseriate exodermis with Casparian bands and suberin lamellae, although there may be some secondary, cellulosic thickening. The Cabombaceae are characterized by small roots with an endodermis with Casparian bands and uneven suberin lamellae, aerenchyma without sclereids or diaphragms, and an exodermis with Casparian bands and distinctive suberin lamellae. The Nelumbonaceae are distinctly different: Nelumbo has an endodermis of Casparian bands, suberin lamellae, and secondarily lignified walls, an aerenchyma without sclereids or diaphragms, and a multiseriate hypodermis with a uniseriate exodermis of Casparian bands and suberin lamellae, and an inner hypodermis with distinctly lignified walls.