Spiranthes cernua, commonly called the Nodding Ladies'-tresses, is a species of orchid occurring from eastern Canada to the central and eastern United States. Orchidaceae, usually referred to as the Orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. It is currently believed to be the largest family of flowering plants with between 21,950 and 26,049 currently accepted species, found in 880 genera.