Flat: the energy that draws motions into a flat plane; to spread out. This energy counters stick (or stalk) energy, which rises to a point, by forming a thin, flat plane, or a petal. A petal so flattened from vertical energy is like a cumulonimbus cloud flattening out in the stratospheric winds. It is a particular powerful force that signifies a change of state no less than the translation of ice into water or water into steam. Notice that the energy in this state is so pure that it strives for thin-ness, in a  process of extended flattening.

Mariposa Lily Point, Stalk and Petals

Three states of energy in one column of growth.