The name of this genus of orchids is derived from the Greek speira, spiral, and anthos, flower, referring to the spiral arrangement of the flowers along the stem.
The genus is mainly found in the Americas and Asia, with a few hundred species. There are only two species in Italy: Spiranthes spiralis and Spiranthes aestivalis.
The plant is slender, 6 to 30 cm high, with a slim stem covered with a dense fuzz. The greenish white, fragrant flowers also vary in number from 6 to 30 and form an elongated, helical inflorescence. Spiranthes spiralis is a nectar-containing species and is pollinated by bumblebees and honeybees, which begin searching from the lowest flowers, the first to open. This species flowers in September - October, when the soil temperature drops to 11°C. The dark green basal leaves (called rosettes) range from 3 to 7, have an ovate-elliptical shape, and are visible throughout the winter and in spring. They dry up before flowering.
Spiranthes spiralis is very abundant (more than 1600 plants) at Boboli and found in variable numbers in most of the garden plots. It is the first orchid officially found in the Garden in 1716 by the distinguished botanist Pier Antonio Micheli (who called it “Ophrys spiralis autumnalis”), as documented in his manuscripts preserved in the Institute of Botany Library at the University of Florence.