This is predominantly a North American genus with just four of the approximately thirty species present in Europe. There are also a few species that occur as far afield as the Far East and Australia.
genus characteristically has two to six fleshy roots (or
slender tubers if you prefer) and as its name suggests, the flower
spike is twisted on its axis thereby createing a regimented row of
florets that spiral upwards to the tip. Individual flowers are small
and the components of the perianth, including the lip, are more or less
equal in length and so give it a tube like appearance.
is a closely related genus to Goodyera and they share a well
developed and efficient pollination mechanism with a scent that seems
highly attractive to small insects.