InHeliconia thread-like structures connecting the pollen grains are described. These threads are decay products of the walls separating the pollen chambers, and products of the rupture of the mature anthers in the stomium region. The pliable cell threads mix with the pollen and entangle individual grains to form aggregates. This ensures that the pollen becomes embedded in the feathers or attached to the smooth, unsculptured beak of pollinating hummingbirds (Trochilidae).—Structure and origin of theHeliconia threads differ from those of the related genusStrelitzia (Strelitziaceae).