Pterostylis smaragdyna, commonly known as the emerald-lip leafy greenhood, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. Flowering plants have up to ten translucent green flowers with darker green markings. The flowers have an insect-like labellum which is green with a darker green mound at the "head" end. Non-flowering plants have a rosette of leaves but flowering plants lack the rosette, instead having five to seven stem leaves.
Pterostylis longifolia, is a terrestrial, perennial, deciduous, herb with an underground tuber. Non-flowering plants have a rosette of between three and five lance-shaped leaves, each leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Flowering plants have up to ten translucent green flowers with darker green markings on a flowering spike NaNsigfig=1NaNsigfig=1 high. The flowering spike has between five and seven linear to lance-shaped stem leaves which are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The dorsal sepal and petals are fused, forming a hood or "galea" over the column with the dorsal sepal having a short point on its tip. The lateral sepals turn downwards, NaNsigfig=1NaNsigfig=1 long, NaNsigfig=2NaNsigfig=2 wide and joined for most of their length. The labellum is insect-like, NaNsigfig=2NaNsigfig=2 long, about 4sigfig=1NaNsigfig=1 wide, pale green with a dark geen stripe along it centre and a dark green mound on the "head" end. Flowering occurs from June to August.[1] [2] [3]
Pterostylis smaragdyna was first formally described in 1993 by David Jones and Mark Clements and the description was published in Muelleria from a specimen collected near Diamond Creek.[4] The specific epithet (smaragdyna) is from the Latin word smaragdinus meaning "emerald green", referring to the colour of the labellum of this species.[5]
The emerald-lip leafy greenhood grows in dry forest and woodland in the south-east corner of New South Wales, central Victoria including the outer suburbs of Melbourne and in the south-east of South Australia.[6]