The florets are white, borne in terminal or axillary,
peduncled, paniculate and the heads are approximately 0.5 cm in diameter.
Some of the collections determined as Trapa americana appear more like Hemitrapa than Trapa (e.g., see illustrations of the
peduncled specimens of Brown, 1935, 1937).
It differs in the degree of inflorescence compounding, proportion of spikes that are
peduncled, total number of spikes, as well as leaf width and the proportionate length of inflorescence bracts.