''Pterostylis ventricosa'', commonly known as the pot-bellied greenhood orchid, is a recently described and critically endangered species of orchid
endemic to a small area of
New South Wales, Australia. As with similar
orchids, the flowering plants differ from those which are not flowering. The non-flowering plants have a
rosette of leaves but the flowering plants lack a rosette at the base but have up to six tiny green, white and brown flowers.
Description
''Pterostylis ventricosa'' is a terrestrial,
perennial,
deciduous,
herb
In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...
with an underground
tuber and when not flowering, a rosette of four to nine dark green, egg-shaped leaves which lie flat on the ground. Each leaf is long and wide. Flowering plants have up to six well-spaced flowers long and about wide borne on a thin, wiry spike high. One or two leaf rosettes are arranged on the side of the flowering spike. The flowers are green and white, swollen at the base and taper towards a bright reddish-brown tip. The dorsal sepal and
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 fused, forming a hood or "galea" over the
column
A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...
. The dorsal sepal is erect near the base but then curves forward and is long and wide. The petals are slightly longer than the dorsal sepal. The
lateral sepals are erect, held closely against the galea with thread-like tips about 3mm long reaching just past the top of the galea. The
labellum is about long, wide, dark brown and white, curved and barely visible above the sinus.
Taxonomy and naming
This greenhood was first formally described in 2008 by
D.L.Jones who gave it the name ''Speculantha ventricosa'' and published the description in ''The Orchadian''.
In 2010, Gary Backhouse changed the name to ''Pterostylis ventricosa''.
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 ...
(''ventricosa'') is a
Latin word meaning "pot-bellied" or "bulging",
and their common name reflects their colour and shape that resembles to having
pot belly.
Distribution and habitat
The tiny greenhood mostly grows in tall forest with a dense understorey, but sometimes in disturbed areas, including roadsides. It occurs near
Nowra,
Tallong
Tallong is in the traditional lands of the Gundungurra people. It is a village within the Southern Tablelands region of New South Wales, Australia, in Goulburn-Mulwaree Council. The village is located just outside the southern extremity of the ...
,
Mittagong,
in the
Jervis Bay area,
Shoalhaven and (discovered in May 2021) in the
Southern Highlands of New South Wales.
Ecology
While the exact processes are not clear, this orchid has a relationship with
fungi in the soil (hence does well after wet weather), and it is thought that they could play a role in the
ecosystem with insects and other pollinators.
[
]
Conservation
''Pterostylis ventricosa'' is classed as "critically endangered" under the New South Wales '' Biodiversity Conservation Act 2016 '', the successor to the ''Threatened Species Conservation Act 1995
The ''Threatened Species Conservation Act 1995 (TSC Act)'' was enacted by the Parliament of New South Wales in 1995 to protect threatened species, populations and ecological communities in NSW. In 2016 it was replaced by the '' Biodiversity Co ...
''. The main threats to the species are land clearing, disturbance by off-road vehicles, grazing by livestock and illegal collection.[ A spokesperson said that the find demonstrated that the New South Wales Government’s "Saving our Species" (SoS) program (which commits to increasing the number of threatened species that are secure in the wild in NSW for 100 years) was having a positive effect on biodiversity.]
References
{{Taxonbar, from=Q17329277
ventricosa
Endemic orchids of Australia
Orchids of New South Wales
Plants described in 2008