''Pterostylis obtusa'', commonly known as the blunt-tongue greenhood, is a species of

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

. It is distinguished from similar greenhood orchids by its thick, flat, platform-like

sinus Sinus may refer to: Anatomy * Sinus (anatomy), a sac or cavity in any organ or tissue ** Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including: *** Maxillary sinus, is the largest of the paranasal sinuses, ...

and blunt labellum which is only just visible above the sinus.

Description

''Pterostylis obtusa'' has a rosette of between three and six dark green, egg-shaped, crinkled leaves, each leaf long and wide. A single shiny, bright green and white flower is borne on a flowering spike high. There are between three and five stem leaves on the flowering spike. The flowers are long and wide. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

curves forward in its upper half and has a thread-like tip about long. The edges of the

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are flared and the sinus is flat and platform-like with a rolled edge. The

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

sepals have thread-like tips long. The labellum is long, wide, green, blunt and is just visible above the sinus. Flowering occurs from February to June.

Taxonomy and naming

''Pterostylis obtusa'' was first described in 1810 by Robert Brown and the description was published in ''

Prodromus Florae Novae Hollandiae et Insulae Van Diemen ''Prodromus Florae Novae Hollandiae et Insulae Van Diemen'' (Prodromus of the Flora of New Holland and Van Diemen's Land) is a flora of Australia written by botanist Robert Brown and published in 1810. Often referred to as ''Prodromus Flora Novae ...

''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''obtusa'') is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word meaning "blunt" or "dull".

Distribution and habitat

The blunt-tongue greenhood grows among grass in moist places on the ranges and tablelands of New South Wales and on

Lord Howe Island Lord Howe Island (; formerly Lord Howe's Island) is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, part of the Australian state of New South Wales. It lies directly east of mainland P ...

. Specimens from

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

are '' Pterostylis atrans''.

References

{{Taxonbar, from=Q15500078 obtusa Endemic orchids of Australia Orchids of New South Wales Plants described in 1810