Spiranthes spiralis, commonly known as autumn lady's-tresses, is a palearctic orchid which in Europe blooms in August and September. It is characterised by a spiral inflorescence produced after the leaves have died down. The inflorescence can be very small (as little as 50 millimetres or 2.0 inches high) especially in short grazed grassland. In Western Europe it occurs most frequently in close cropped grassland overlying chalk or limestone.
S. spiralis is a short tuberous perennial which reaches heights between 5 and 30 centimeters. The stem is stickily-hairy.The plant has two tubers as storage organs, rarely, one or three. From Autumn two new tubers are formed and the old tubers lowly die off. The shiny oval-elliptical foliage leaves form a basal rosette close to the ground and to one side of the flower-spike. There are from three to seven and they have a length of 1.5 to 3.5 cm and a width of 1 to 1.5 cm. The leaves are often withered by flowering time. The stem leaves are scale-like and overlapping;the bracts are shorter than the flowers.
The flowers are white, 6-7mm long. There are up to 20 borne in a slender spiral 3 to 12 cm long.The outer 2 sepals are spreading, the upper sepal and the petals fuse to form a tube with the lip. The lip has up-curved edges and is yellowish-green. The edge of the lip is notched and appears viewed up close as frayed.
The growth cycle differs from most other European orchids. Between July and August the flowering stem begins to grow. At this time, no leaves are visible. Between late August and early October, the leaves develop next to the flowering stem. They survive the winter and grow until the beginning of summer when they wither.The next flowering stem then grows from the center of the withered rosette of leaves .
Dry grassy places, meadows, garigue, heaths, pine woodland, generally on calcareous soils..From Wikipedia, the free encyclopedia
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