shell orchid

The term "shell orchid" can refer to certain species within the genus Pterostylis, which belongs to the orchid family Orchidaceae. These terrestrial orchids are native to Australasia and can be found in various habitats, from rainforests to grasslands.1

Greenhood orchids, as they are commonly known, have unusual, dull-colored, hooded flowers designed to trap insects for pollination. When an insect enters the flower seeking nectar, a hinged lip seals the entrance. The insect must then exit through a special tunnel, inadvertently picking up pollen packets (pollinia) on its way out, which are then transferred to other flowers. Some Pterostylis species, like the jug orchid (Pterostylis recurva) and the hooded orchid (P. banksii), are sometimes called shell orchids.1