[4] The stems are hairless and float prostrate across the top of the water, then grow upright from these bases to support leaves.

[5] Hymenachne has been shown to increase the stem length between nodes to keep leaves above water during periods of flooding.

[5] Researchers at the University of Florida have seen multiple panicles per plant originating from branching at a single node.

[10][11][12] Hymenachne prefers constantly inundated soil and is known to survive comfortably in about a meter of water for 20 years.

[15][16] Hymenachne has also been found in water greater than 4m deep persisting in floating mats, likely dislodged after a storm event.

[17] Hymenachne is known to colonize and form dense monocultures in floodplains, roadside ditches, and lake margins in invaded and native areas.