A rheophyte is a plant that lives in fast moving water currents in an environment where few other organisms can survive.
The amount of force produced by these currents, and the damaging debris they can carry, makes this environment inhospitable to most plants.
In order to prevent being uprooted by the rushing currents, rheophytes have an extremely strong wide spreading root system.
When low water levels occur, obligate rheophytes often quickly begin to flower to take advantage of these occurrences.
Examples of rheophytic plants are Asplenium obtusifolium, Osmunda lancea, and Tectaria lobbii (ferns) and Gosong brevipedunculata (an aroid).