Pterostylis alobula (Greenhood) was Diplodium alobulum

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Subtribe: Pterostylidinae
Genus: Pterostylis
Species: P. alobula
Binomial name:  Pterostylis alobula
Synonym: Diplodium alobulum
Common name: Greenhood

There has been a taxon swap affecting Diplodium alobulum (Greenhood orchid) replaced with Pterostylis alobula.
Diplodium alobulum (Hatch) D.L.Jones, Molloy & M.A.Clem. (2002) is now regarded as a synonym of <em>Pterostylis alobula(Hatch) L.B.Moore (1969). For details, see Janes, J.K.; Duretto, M.F. 2010: A new classification for subtribe Pterostylidinae (Orchidaceae), reaffirming Pterostylis</em> in the broad sense. Australian Systematic Botany 23: 260-269.

Pterostylis alobula is a terrestrial deciduous genus of some 100 or so species of orchids found mainly in New Zealand, Australia, Papua New Guinea and New Caledonia. The common name of this orchid is Greenhood - a number of species have green flowers with the dorsal sepal forming a "hood" over the rest of the flower. The name Pterostylis is based on the Greek words meaning winged column (pteron - a wing, stylis - a column). In a number of species, the flower has a hinged lip that swings back when touched by an insect, forming a tube with the column and wings. The trapped insect is then forced to crawl out of the tube, removing the pollinia in the process.

[ Diplodium alobulum was named Pterostylis alobula.-1.JPG 
] Diplodium alobulum was named Pterostylis alobula..JPG

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