[3] Epipactis helleborine can grow to a maximum height of 1 m (3 ft 3 in) or more under good conditions, and has broad dull green leaves which are strongly ribbed and flat.

[4][5] The flowers are arranged in long drooping racemes with dull green sepals and shorter upper petals.

[10] In North America, it is an introduced species and widely naturalized mostly in the Northeastern United States, eastern Canada and the Great Lakes Region, but also in scattered locations in other parts of the continent.

[18] These roadside orchids exhibit special features such as large plant size and greater ability to produce flowers.

[19][20] Eight populations of Epipactis helleborine in central Europe (Lower Silesia, Poland) had their nectar studied and they were found to contain naturally occurring oxycodone (as well as another narcotic-like opioid) in minute amounts.

[21] Epipactis helleborine requires a mycorrhizal symbiosis to germinate successfully and remains partially dependent upon the fungus when plants mature, however it is not particularly selective among fungal species.