About Spiranthes arcisepala M.C.Pace
Spiranthes arcisepala is a terrestrial, perennial, deciduous herb in the orchid family. Like many other Spiranthes orchids, it is stemless, with one to four basal leaves that remain present through flowering (anthesis). Its flowers are arranged in a spiral spike around the central stem, and the whole plant can reach a maximum height of 46 cm (18 in). As with all orchids, each flower has three petals and three sepals. All petals and sepals are white, roughly 10 mm (0.4 in) long, and all except the lower petal (called the lip) are less than 3 mm (0.1 in) wide. It looks very similar to Spiranthes incurva, but can be distinguished by its lateral sepals, which bend downward so their tips often sit lower than the tip of the lip. This characteristic downward arching of the sepals gives the species its scientific name arcisepala, from the Latin words arcus meaning arching and sepalorum meaning sepals. Spiranthes arcisepala (common name Appalachian ladies' tresses) is primarily distributed across the Appalachian Mountains, ranging from Nova Scotia south to western Virginia. Its range also extends into northern Ohio, Indiana, and southern Michigan. It grows in wet habitats including fens, bogs, and seeps.
