Two-bristle Greenhood Orchid
Flower - labellum open
Murray Mallee Region
Two-bristle Greenhood Orchid
Hood, side
Two-bristle Greenhood Orchid (Pterostylis biseta)Class: Plants (Plantae) - Land Plants (Charophyta) - Land Plants (Equisetopsida)
Order: Asparagus (Asparagales)
Family: Orchid (Orchidaceae)
Species: Two-bristle Greenhood Orchid (Pterostylis biseta)
This Photo:     Flower - labellum, side
Other names: Rustyhood or Veined Greenhood

General Species Information:
Found in the Murray Mallee SA and possibly elsewhere
These are fascinating flowers. The two bristles are sensitive to motion. John Smyth tells us this is called an "irritable labellum". An insect will land on the labelum, attracted to the flower by scent. This will trigger the bristles to close the labellum, trapping the insect inside the flower tube. It's only way out is to follow the tube and escape. In the process is brushed against the pollen, thereby fertilising this flower, or taking it's pollen to another

Copyright © 2010-2024 Brett & Marie Smith. All Rights Reserved. Photographed 25-Oct-2010
This species is classed as RA (Rare) in the Murray Mallee, SA, by DENR (Regional Species Status Assessments, July 2010)