''Pterostylis nutans'', commonly known as the nodding greenhood or the parrot's beak orchid, 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 ...

to eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. Nodding greenhoods have flowers which "nod" or lean forwards strongly, have a deeply notched sinus and a curved, hairy labellum. Pterostylis nutans leaves

Description

''Pterostylis nutans'' has a rosette of between three and six egg-shaped to elliptic leaves, each leaf long and wide. The leaves are dark green, have a wavy edge and a distinct petiole. A single translucent white flower with green stripes and brown colouration is borne on a flowering spike high, the flower strongly "nodding" or leaning forwards. The flowers are long, wide. There is a wide gap at each side of the flower between 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 and the lateral

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 ...

s. The lateral sepals curve forwards, have a tapering tip, long and there is a deeply notched sinus between them. The labellum protrudes from the flower and is long, wide, curved, blunt, green and brown and covered with short, bristly hairs. Flowering occurs from March to December.

Taxonomy and naming

''Pterostylis nutans'' was first described in 1810 by Robert Brown and the description was published in '' Prodromus Florae Novae Hollandiae et Insulae Van Diemen''. 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 ...

(''nutans'') 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 "nodding" or "drooping".

Distribution and habitat

Nodding greenhoods often occur in large colonies in moist, protected forest environments and is native to the

n states of

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

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

, Victoria,

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 ...

and

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

as well as the

Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...

. In Queensland it grows as far north as the

Atherton Tableland The Atherton Tableland is a fertile plateau which is part of the Great Dividing Range in Queensland, Australia. The principal river flowing across the plateau is the Barron River. It was dammed to form an irrigation reservoir named Lake Tina ...

, in the eastern half of New South Wales, the southern half of Victoria, the south-eastern corner of South Australia and in Tasmania, including

King King is the title given to a male monarch in a variety of contexts. The female equivalent is queen, which title is also given to the consort of a king. *In the context of prehistory, antiquity and contemporary indigenous peoples, the tit ...

and Flinders Islands. It has also been found in

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

but is regarded as a

vagrant Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, temporar ...

there because the insect pollinator is not present in that country. There is a single population remaining near the Waihaha River, although there have been records from Kaitaia and

Castor Bay Castor Bay is a bay and suburb of the North Shore, located in Auckland which is in the North Island of New Zealand. Located between Milford and Campbells Bay, it is part of the East Coast Bays. To the east lies the islands of Rangitoto and Motu ...

Ecology

This greenhood is pollinated by a particular species of

fungus gnat Fungus gnats are small, dark, short-lived gnats, of the families Sciaridae, Diadocidiidae, Ditomyiidae, Keroplatidae, Bolitophilidae, and Mycetophilidae (order Diptera); they comprise six of the seven families placed in the superfamily Sciaroide ...

, attracted by a kairomone produced by the flower's labellum. The labellum tips the insect into the flower, and in attempting to escape, it comes into contact with the sexual organs of the flower and pollination occurs.

Use in horticulture

''Pterostylis nutans'' is easily grown in pots containing a free-draining, sandy mix. The plants require regular watering during their growing period, to be kept dry during dormancy and to be repotted annually.

References

{{Taxonbar, from=Q7256926 nutans Orchids of the Australian Capital Territory Orchids of New South Wales Orchids of Queensland Orchids of South Australia Orchids of Tasmania Orchids of Victoria (Australia) Plants described in 1810