| Noun | 1. | giant helleborine - orchid growing along streams or ponds of western North America having leafy stems and 1 greenish-brown and pinkish flower in the axil of each upper leafEpipactis, genus Epipactis - genus of hardy orchids with leafy-bracted racemes of greenish or purplish irregular flowers helleborine - any of various orchids of the genus Epipactis | |