About Spiranthes romanzoffiana Cham.
Hooded lady's tresses, whose scientific name is Spiranthes romanzoffiana Cham., is a perennial orchid with a fleshy rootstock. It produces shoots with lanceolate leaves, and its flowers grow in three spirally twisted rows. Each scented flower has united sepals and petals that form the lip of a tube; the labellum, or lower petal, is white with green veins. This plant blooms in late summer. Its flowers are pollinated by insects, and it produces tiny, dust-like seeds that are dispersed by wind. It can also reproduce vegetatively via root tubers, which grow new shoots as the old parts of the plant die. This orchid forms an association with a mycorrhizal fungus that supplies it with essential nutrients. It was first formally described by German botanist Adelbert von Chamisso, who named it to honor his patron Nikolay Rumyantsev. Rumyantsev financed the 1815–1818 scientific exploration of the Americas where Chamisso collected this orchid. It is common across North America, including Canada and the United States, and also grows in a small number of locations in Scotland and Ireland. It is currently considered regionally extinct in England, but was rediscovered in Wales in 2019. The first recorded observation of this species in Ireland was made in 1810 in County Cork. Since that time, it has been found in multiple other locations across Ireland and Northern Ireland, including the Lough Neagh basin, the Mourne Mountains, and the hills of Antrim. It grows along lakeshores and in damp pastures. Its distribution pattern, occurring on both sides of the Atlantic Ocean, remains unexplained and puzzling. Studies of pollinator interactions for this species have only been carried out on West Irish populations; the most common pollinators recorded there are Bombus pascuorum, B. hortorum, and Apis mellifera. No studies have yet been done on the mycorrhizal associations of Irish populations of this orchid. Recent research has identified genetic hybrids in the Ontario, Canada population of this species. Genetic studies have also been completed to assess the genetic diversity of the European population.
