Spiranthes

It has a very wide, almost continuous distribution, mostly in temperate zones of the northern hemisphere: Europe, North Africa, Asia, Australia, New Guinea, the Americas and the Caribbean. It is a provincially endangered orchid, in North America it can be found in Manitoba, Ontario and more than 20 American states. They grow in meadows, fields and savannas but are also found in forests, both on acid and calcareous soil. Most species tend to become weeds in disturbed areas, while they may be scarce in undisturbed areas.

Plants can grow to a height of 12 to 38 cm (4.5 to 15 inches). Spiranthes consists of perennial, terrestrial orchids with clustered, tuberous or rarely fibrous, fleshy roots. The leaves are basal or occasionally cauline (i.e. emerging from the stem). They are variable in shape. They range from broadly ovate to elliptic, or absent at flowering.

The flowering stem has foliaceous sheaths. The stem is erect and spiraling (as the name Spiranthes indicates). It carries persistent, sheathing bracts. The resupinate, tubular flowers are arranged in a more or less spirally twisted, showy or inconspicuous terminal spike. Their color is typically a shade of white or yellowish-white or even pink (as in Spiranthes sinensis).

This genus has undergone many taxonomic changes: originally Spiranthes contained all the species from the subtribe Spiranthinae. In 1920 Schlechter divided this genus in 24 genera. A revision by Williams in 1951 and by Schweinfurth in 1958, inflated the number of species of this genus again. Finally D. Szlachetko, with several studies in the 1990s, divided this genus in several genera, contained in 3 subtribes. During all these changes, there is only one species that has remained taxonomically unchanged: Spiranthes parksii

Spiranthes is derived from the Ancient Greek σπεῖρα (twisted or coiled) and ἄνθος (flower).

Flowers of this genus are commonly popular in Japan, where it is called nejibana (捻花?) (lit.twisting flower.)