Spiranthella nocturnaNight-spiral Flower

About two hours after sunset, fine scales remain scattered in the throat of the open white flowers. No insects were shown in the footage, yet by morning many stigmas carry a pale brown dusting on only one side. The visitor was likely a small, short-tongued noctuid moth. Rather than producing much nectar, the flower seems to rely on scent and a low position along limestone fissures.

At the beginning of the rains, only the base of the spiral-closed flower swells briefly, becoming a dry capsule within about ten days. The seeds are not light enough for wind dispersal; raindrops knock them into the grooves below. This explains the irregular spacing of the stands. They do not crowd the parent plant, but appear at intervals of several tens of centimeters along narrow runnels in the limestone.

At dawn the petals coil sooner and more tightly on mornings with a dry wind. This is best understood as a movement that protects pollen and stigma from ultraviolet light and dehydration. People grazing livestock or gathering honey around the tsingy remembered this tightness when deciding movements before the rains. It was not divination, but an empirical rule drawn from years of repeated dry mornings.