Pterostylis spissa

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Cygnet greenhood
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Genus: Pterostylis
Species:P. spissa
Binomial name
Pterostylis spissa
(D.L.Jones) G.N.Backh. [1]
Synonyms [2]

Pterostylis spissa, commonly known as the cygnet greenhood, is a plant in the orchid family Orchidaceae and is endemic to Victoria. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground and flowering plants have up to twelve small, green flowers which have a green labellum with a dark green beak-like appendage.

Orchidaceae family of plants

The Orchidaceae are a diverse and widespread family of flowering plants, with blooms that are often colourful and fragrant, commonly known as the orchid family.

Endemism Ecological state of being unique to a defined geographic location or habitat

Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species that are restricted to a defined geographical area.

Victoria (Australia) State in Australia

Victoria is a state in south-eastern Australia. Victoria is Australia's smallest mainland state and its second-most populous state overall, making it the most densely populated state overall. Most of its population lives concentrated in the area surrounding Port Phillip Bay, which includes the metropolitan area of its state capital and largest city, Melbourne, Australia's second-largest city. Victoria is bordered by Bass Strait and Tasmania to the south, New South Wales to the north, the Tasman Sea to the east, and South Australia to the west.

Contents

Description

Pterostylis spissa, is a terrestrial, perennial, deciduous, herb with an underground tuber. It has a rosette of between five and nine leaves 5–15 mm (0.2–0.6 in) long and 3–8 mm (0.1–0.3 in) wide, lying flat on the ground. Between two and twelve yellowish-green flowers with darker green stripes are crowded together on a flowering stem up to 120 mm (5 in) high with between four and six stem leaves with their bases wrapped around it. The flowers are 6–8 mm (0.2–0.3 in) long with the dorsal sepal and petals joined to form a hood called the "galea" over the column. The dorsal sepal is gently curved but suddenly curves downward near the tip and is about the same length as the petals. The lateral sepals turn downwards, 3–4 mm (0.1–0.2 in) long, 4–5 mm (0.2–0.2 in) wide and fused together forming a cup with tips about 2 mm (0.08 in) long and parallel to each other. The labellum is about 2 mm (0.08 in) long and wide, and pale green with a dark green, beak-like appendage. Flowering occurs in October and November. [3] [4]

Perennial plant Plant that lives for more than two years

A perennial plant or simply perennial is a plant that lives more than two years. Some sources cite perennial plants being plants that live more than three years. The term is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth from trees and shrubs, which are also technically perennials.

Deciduous trees or shrubs that lose their leaves seasonally

In the fields of horticulture and botany, the term deciduous (/dɪˈsɪdʒuəs/) means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit.

Herbaceous plant Plant which has no persistent woody stem above ground

Herbaceous plants in Botany, frequently shortened to herbs, are vascular plants that have no persistent woody stem above ground. Herb has other meanings in cooking, medicine, and other fields. Herbaceous plants are those plants that do not have woody stems, they include many perennials, and nearly all annuals and biennials, they include both forbs and graminoids.

Taxonomy and naming

The cygnet greenhood was first formally described in 2009 by David Jones and given the name Hymenochilus spissus. The description was published in Australian Orchid Research from a specimen collected near Woorndoo. [5] In 2010, Gary Backhouse changed the name to Pterostylis spissa. [1] The specific epithet (spissa) is a Latin word meaning "close", "dense" or "thick". [6]

David Lloyd Jones is an Australian horticultural botanist and the author of a large number of books and papers, especially on Australian orchids.

Woorndoo Town in Victoria, Australia

Woorndoo is a town in the Western District of Victoria, Australia. The town is in the Shire of Moyne local government area, 259 kilometres (161 mi) west of the state capital, Melbourne. At the 2016 census, Woorndoo and the surrounding area had a population of 169. The population of the town proper is around 50.

Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical nomenclature is Linnaeus' Species Plantarum of 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN). Fossil plants are also covered by the code of nomenclature.

Distribution and habitat

Pterostylis spissa is restricted to remnant native grassland among basalt rocks in a few locations to the west of Melbourne. [4]

Melbourne City in Victoria, Australia

Melbourne is the capital and most populous city of the Australian state of Victoria, and the second most populous city in Australia and Oceania. Its name refers to an urban agglomeration of 9,992.5 km2 (3,858.1 sq mi), comprising a metropolitan area with 31 municipalities, and is also the common name for its city centre. The city occupies much of the coastline of Port Phillip bay and spreads into the hinterlands towards the Dandenong and Macedon ranges, Mornington Peninsula and Yarra Valley. It has a population of approximately 5 million, and its inhabitants are referred to as "Melburnians".

Conservation

Pterostylis spissa is critically endanged, only known from a few roadside reserves. [3]

Related Research Articles

<i>Pterostylis cycnocephala</i> species of plant

Pterostylis cycnocephala, commonly known as the swan greenhood, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It has a rosette of leaves and up to 24 green flowers which have a labellum with a dark green, beak-like appendage. It is widespread and common from the Darling Downs in Queensland to Tasmania, usually growing with grasses.

<i>Pterostylis crassicaulis</i> species of plant

Pterostylis crassicaulis, commonly known as the alpine swan greenhood, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It has a rosette of leaves and up to 18 bluish-green and white flowers with dark green stripes. The flowers have a labellum with a dark green, beak-like appendage. It is similar to P. cycnocephala but is more robust and grows at higher altitudes.

<i>Pterostylis bicolor</i> species of plant

Pterostylis bicolor, commonly known as the black-tip greenhood, is a plant in the orchid family Orchidaceae and is endemic to south-eastern Australia. It has a rosette of leaves and when flowering, three to ten well-spaced, bright green flowers with a blunt, greenish-black appendage on the labellum. It is similar to the swan orchid, Pterostylis cycnocephala but that species has a beak-like appendage and crowded flowers.

<i>Pterostylis jonesii</i> species of plant

Pterostylis jonesii, commonly known as the montane leafy greenhood, is a plant in the orchid family Orchidaceae and is endemic to a small area of south-eastern Australia. Individual plants have either a rosette of three to six leaves or a flowering spike with up to eleven flowers and five to seven stem leaves. The flowers are translucent green with faint darker green lines and have a brownish-yellow labellum with a dark stripe.

Pterostylis alata, commonly known as the striped greenhood, is a species of orchid endemic to Tasmania. 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 have a single flower with leaves on the flowering spike. This greenhood has a white flower with prominent dark green stripes and a sharply pointed, brown-tipped dorsal sepal. Similar greenhoods growing on the Australian mainland were formerly known as Pterostylis alata but are now given the name Pterostylis striata.

Pterostylis agrestis is a plant in the orchid family Orchidaceae and is endemic to Victoria. It has a rosette of leaves and when flowering, up to fourteen transparent green flowers with a blunt, greenish-black appendage on the labellum. It is similar to the black-tip greenhood, Pterostylis bicolor but that species has larger, less crowded flowers and is found in different habitats.

Pterostylis brumalis, commonly known as the kauri greenhood or winter greenhood, is a species of orchid endemic to New Zealand. There is a rosette of leaves at the base of both flowering and non-flowering plants. Flowering plants have a white flower with narrow green stripes and a dorsal sepal which bends forward strongly while the petals spread widely, giving the flower a cobra-like appearance.

Pterostylis clivicola is a plant in the orchid family Orchidaceae and is endemic to a small area near the border between New South Wales and Victoria. It has a rosette of leaves and up to fourteen green flowers which have a labellum with a dark green, beak-like appendage.

Pterostylis conferta, commonly known as the leprechaun greenhood or basalt midget greenhood, is a plant in the orchid family Orchidaceae and is endemic to Victoria. It has a rosette of leaves at the base of the flowering stem and up to sixteen pale green flowers in a short, crowded spike. It is a very rare orchid, similar to P. mutica, its distribution much reduced by urbanisation and agriculture.

Pterostylis dubia, commonly known as the blue-tongued greenhood, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. It has a rosette of fleshy leaves at its base and a dark green and white flower with narrow petals and a dark blue-green labellum.

Pterostylis incognita, commonly known as the Sale greenhood, is a plant in the orchid family Orchidaceae and is endemic to Victoria. It has a rosette of leaves and when flowering, up to twelve crowded flowers on a stem with a rosette at the base. The type specimen was collected near Sale in 1895 but was not formally described or given a name until 2009, by which time it was presumed extinct.

Pterostylis macrosepala is a plant in the orchid family Orchidaceae and is endemic to New South Wales where it grows on the central-west slopes. As with similar greenhoods, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of leaves flat on the ground but the flowering plants have up to eight translucent green flowers with narrow, dark green stripes and up to ten stem leaves.

<i>Pterostylis prasina</i> species of plant

Pterostylis prasina, commonly known as the mallee leafy greenhood, is a plant in the orchid family Orchidaceae and is endemic to southern continental Australia. Non-flowering have a rosette of leaves on a short stalk, but flowering plants lack the rosette and have up to eight pale green and translucent green flowers with darker green lines. The flowers have a pale green labellum with a darker central line. It is a common and widespread greenhood in parts of Victoria and South Australia.

Pterostylis pratensis, commonly known as the Liawenee greenhood, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground. Flowering plants have up to twelve crowded white flowers with prominent green stripes. This greenhood only grows in low, exposed subalpine tussock grassland.

Pterostylis rubenachii, commonly known as the Arthur River greenhood, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground and flowering plants have up to seven crowded, transparent green flowers with darker green stripes.

Pterostylis stenosepala, commonly known as the narrow-sepalled leafy greenhood, is a plant in the orchid family Orchidaceae and is endemic to New South Wales. Flowering plants have up to six shiny, translucent green flowers with darker green stripes. The flowers have an insect-like labellum which is green with a dark green mound on its upper end. Non-flowering plants have a rosette of leaves on a stalk, but flowering plants lack the rosette, instead having between four and eight stem leaves.

Pterostylis tanypoda, commonly known as the swan greenhood, is a species of greenhood orchid endemic to New Zealand. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground and flowering plants have up to seven crowded, inconspicuous bluish-green and white-striped flowers.

<i>Pterostylis torquata</i> species of plant

Pterostylis torquata, commonly known as the collared greenhood, is a species of orchid endemic to New South Wales. As with similar greenhoods, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of leaves flat on the ground but the flowering plants have a single flower with leaves on the flowering stem. This greenhood has a white flower with dark green and dark brown markings, although in some areas, the flowers lack the brown markings. The sinus between the lateral sepals is platform-like.

Pterostylis ziegeleri, commonly known as the Cape Portland greenhood, is a plant in the orchid family Orchidaceae and is endemic to Tasmania. Both flowering and non-flowering plants have a rosette of leaves lying flat on the ground and flowering plants have up to eight crowded translucent, pale green flowers with darker green veins.

Pterostylis flavovirens, commonly known as the coastal banded greenhood, is a plant in the orchid family Orchidaceae that is endemic to South Australia. As with other similar orchids, non-flowering plants differ from those in flower. Flowering plants have up to seven pale to translucent green flowers with darker green stripes. The flowers have an insect-like labellum which is yellowish green with a slightly darker green stripe along its centre. Non-flowering plants have a rosette of leaves on a stalk, but flowering plants lack the rosette, instead having three to six stem leaves.

References

  1. 1 2 "Pterostylis spissa". APNI. Retrieved 18 July 2017.
  2. "Pterostylis spissa". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  3. 1 2 Jeanes, Jeff. "Pterostylis spissa". Royal botanic Garden Melbourne; vicflora. Retrieved 18 July 2017.
  4. 1 2 "Cygnet greenhood". Biodiversity of the Western Volcanic Plains. Retrieved 18 July 2017.
  5. "Hymenochilus spissus". APNI. Retrieved 18 July 2017.
  6. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 791.