Hammer Orchids

Drakaea is a genus of 10 species in the plant family Orchidaceae commonly known as hammer orchids. All ten species occur only in the south-west of Western Australia. Hammer orchids are characterised by an insectoid labellum that is attached to a narrow, hinged stem, which holds it aloft. The stem can hinge only backwards, where the broadly winged column carries the pollen and stigma. Each species of hammer orchid is pollinated by a specific species of thynnid wasp. Thynnid wasps are unusual in that the female is flightless and mating occurs when the male carries a female away to a source of food. The labellum of the orchid resembles a female thynnid wasp in shape, colour and scent. Insect pollination involving sexual attraction is common in orchids but the interaction between the male thynnid wasp and the hammer orchid is unique in that it involves the insect trying to fly away with a part of the flower.