Drakaea
Encyclopedia
Drakaea is an endangered genus of orchid that is native to Australia
. Orchids in this genus are commonly called "Hammer Orchids". The common name refers to the shape of the orchid, and the way it moves, resembling a hammer. The genus was named after Miss Drake, a botanical artist who drew orchids and other plants to assist taxonomists in England in the 19th century.
Members of the Drakaea genus are characterized by an insectival labellum
that is attached to a narrow, hinged stem, which holds it aloft. The stem can only hinge backwards, where the broadly winged column carries the pollen
and stigma.
Hammer orchids have specified their method of pollination
by only being pollinated by the Thynnid wasp
. The female wasps being flightless wait on top of stems for the males, to fly in and carry them off. Then they will mate in mid-flight. Hammer orchids being deceitful mimic the female wasps, their labellum being similar in color and in structure to the female wasp's abdomen
. The orchids also produce pheromones very similar to those that the female wasp produces.The female wasp produces the pheromones to attract the male. When the male becomes attracted by the pheromones released by the orchid and its shape, it tries to fly away with the labellum, which makes the stem holding it move backwards. Which in turn brings the male wasp's thorax
in contact with the sticky pollen packet. The male wasp will become tired of trying and fly off. In order for the Hammer orchid to be successfully pollinated, the male wasp must be fooled by another individual orchid, where it goes through the same procedure. But this time the pollen is deposited in the stigma, and so that plant has been pollinated. This form of symbiosis
is not mutualistic, the wasp getting nothing in return for having pollinated the hammer orchid. This method does not always work for the plant's pollination because the male wasp does not always fall for it, ecpecially during mating season when there are more active female wasps..
There are at least ten species in this genus.
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Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. Orchids in this genus are commonly called "Hammer Orchids". The common name refers to the shape of the orchid, and the way it moves, resembling a hammer. The genus was named after Miss Drake, a botanical artist who drew orchids and other plants to assist taxonomists in England in the 19th century.
Members of the Drakaea genus are characterized by an insectival labellum
Labellum
Labellum is the Latin diminutive of labium, meaning lip. These are anatomical terms used descriptively in biology, for example in Entomology and botany.-Botany:...
that is attached to a narrow, hinged stem, which holds it aloft. The stem can only hinge backwards, where the broadly winged column carries the pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
and stigma.
Hammer orchids have specified their method of pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
by only being pollinated by the Thynnid wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
. The female wasps being flightless wait on top of stems for the males, to fly in and carry them off. Then they will mate in mid-flight. Hammer orchids being deceitful mimic the female wasps, their labellum being similar in color and in structure to the female wasp's abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. The orchids also produce pheromones very similar to those that the female wasp produces.The female wasp produces the pheromones to attract the male. When the male becomes attracted by the pheromones released by the orchid and its shape, it tries to fly away with the labellum, which makes the stem holding it move backwards. Which in turn brings the male wasp's thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
in contact with the sticky pollen packet. The male wasp will become tired of trying and fly off. In order for the Hammer orchid to be successfully pollinated, the male wasp must be fooled by another individual orchid, where it goes through the same procedure. But this time the pollen is deposited in the stigma, and so that plant has been pollinated. This form of symbiosis
Symbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
is not mutualistic, the wasp getting nothing in return for having pollinated the hammer orchid. This method does not always work for the plant's pollination because the male wasp does not always fall for it, ecpecially during mating season when there are more active female wasps..
There are at least ten species in this genus.
List of species
- Drakaea andrewsiae Hopper & A.P.Br., Austral. Syst. Bot. 20: 261 (2007).
- Drakaea concolor Hopper & A.P.Br., Austral. Syst. Bot. 20: 262 (2007).
- Drakaea confluens Hopper & A.P.Br., Austral. Syst. Bot. 20: 264 (2007).
- Drakaea elastica Lindl., Sketch Veg. Swan R.: 56 (1840).
- Drakaea glyptodon Fitzg., Gard. Chron. 1882(1): 494 (1882).
- Drakaea gracilis Hopper & A.P.Br., Austral. Syst. Bot. 20: 271 (2007).
- Drakaea isolata Hopper & A.P.Br., Austral. Syst. Bot. 20: 273 (2007).
- Drakaea livida J.Drumm., London J. Bot. 1: 628 (1842).
- Drakaea micrantha Hopper & A.P.Br., Austral. Syst. Bot. 20: 278 (2007).
- Drakaea thynniphila A.S.George, Nuytsia 5: 60 (1984).