SEAGO, JAMES L., JR. Department of Biology, SUNY, College at Oswego, Oswego, NY 13126. - The root cortex of the water lilies and lotuses.
The roots of selected members of the Nymphaeaceae, Cabombaceae, and
Nelumbonaceae were examined to determine root cortex characteristics
in order to distinguish among the families. Each family has a
characteristic root cortex structure. Members of the Nymphaeaceae
typically have an endodermis with Casparian bands only, an extensive,
hexagonally patterned aerenchyma with branched sclereids spreading
from semi-regular hexagon cells and with transverse diaphragms, and a
multiseriate hypodermis composed of a uniseriate exodermis with
Casparian bands and suberin lamellae and with cellulose-thickened cell
walls in some species. The Cabombaceae have small roots with an
endodermis with Casparian bands and suberin lamellae, a simple
aerenchyma without sclereids or transverse diaphragms, and a
uniseriate exodermis with Casparian bands and distinctive suberin
lamellae. The Nelumbonaceae have an endodermis with Casparian bands,
suberin lamellae, and secondarily lignified cell walls, a hexagonally
patterned aerenchyma without sclereids or transverse diaphragms, and a
multiseriate hypodermis with a uniseriate exodermis of Casparian bands
and suberin lamellae and an inner hypodermis with distinct patterns of
lignified cell walls.
Key words: aerenchyma, endodermis, exodermis, lotuses, root cortex, water lilies