In some astelic L- ~ stems (Nymphaeaceae) the number of bundles is greatly increased and they are scattered throughout the ground tissue.
The most remarkable feature here is the class of Liorhizal Dicotyledons, which includes only the families of Nymphaeaceae and Gramineae.
But the presence of a second cotyledon in grasses is extremely doubtful, and though there may be ground for reconsidering the position of Nymphaeaceae, their association with the grasses as a distinct class is not warranted by a comparative examination of the members of the two orders.
Flowers which are cyclic at one portion and spiral at another, as in many Ranunculaceae, are termed hemicyclic. In spiral flowers the distinction into series is by no means easy, and usually there is a gradual passage from sepaloid through petaloid to staminal parts, as in the water-lily family, Nymphaeaceae (figs.