Inflorescence architecture has evolved through interactions with pollinators, affecting display effectiveness and self-pollination relevance. Spiranthes australis (Orchidaceae), or Ladies Tresses, shows remarkable within-population variation in inflorescence morphology, particularly in the strength and direction of the floral helix. The underlying mechanisms for this variation remain poorly understood. We first investigated the morphological basis of inflorescence variation and then evaluated its effects on display and reproductive success. The frequency of clockwise and counterclockwise floral helices did not deviate from a 1:1 ratio across populations. The combination of rotation directions in paired inflorescences on the same individual did not differ from random expectation, whereas their divergence angles were strongly correlated, suggesting random determination of helix direction and genetic control of divergence angle. Morphological analysis showed that variation in divergence angle among individuals was linked to the degree of rachis torsion. A detection test using human participants showed that inflorescence models with small divergence angles were detected more easily than those with large ones. Detection time varied by presentation direction for extreme (small/large) angles but not for intermediate ones, suggesting better all-around visibility in intermediate angles. Field observations revealed that inflorescences with intermediate divergence angles had lower fruit set than those with small or large angles, despite producing the most flowers. As a result, reproductive success did not differ among divergence angle categories. This trade-off may underlie the evolutionary maintenance of within-population variation in divergence angle.