'helmet orchid' definitions:

noun

Any of numerous orchids of the genus Pterostylis having leaves in a basal rosette and green flowers often striped purple or brown or red with the dorsal sepal incurved to form a hood [syn: helmet orchid, greenhood]

noun

Any of several orchids of the genus Coryanthes having racemes of a few musky-scented waxy flowers with a helmet-shaped lip process [syn: helmetflower, helmet orchid]