Epipactis helleborine, the Broad-leaved Helleborine is not really a native orchid but a European import that has naturalized all across the country. We've also seen it in the dunes along the eastern Lake Michigan shore in the state of Michigan, and it is found in many other places around the country.
The plant can be as tall as 80 cm, though the plants we've seen have not been taller than 60 cm. It is usually densely flowered with as many as 50 flowers each 3-4 cm in size. Plants growing in shady conditions, however, may be much smaller with fewer, more widely spaced flowers.
The few leaves are pleated and the flowers are ordinarily green suffused with pink, but there are plain green, yellow and white forms as well, as well as a form with variegated leaves. The plant blooms in August in our area.
The plant was first found in North America near Syracuse, New York, in 1878. Since then it has spread to 31 states and six Canadian Provinces, according to the USDA. We found these plants along a railway line suggesting one possible way in which it has spread.
The blog entry which describes our finding and photographing this orchid can be found at: http://ronaldhanko-orchidhunter.blogspot.com/2010/08/larrabee-state-park.html.