Pterostylis irsoniana

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Greenhood
Pterostylis irsoniana (4283458789).jpg
Pterostylis irsoniana growing near the Routeburn Track
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Genus: Pterostylis
Species:P. irsoniana
Binomial name
Pterostylis irsoniana

Pterostylis irsoniana is a species of greenhood orchid endemic to New Zealand. There are up to five erect leaves on the flowering stem with a single dark green flower with white stripes and a reddish tinge on the tips. It has a distinctive curved labellum with a curled tip with a dark red callus.

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.

New Zealand Country in Oceania

New Zealand is a sovereign island country in the southwestern Pacific Ocean. The country geographically comprises two main landmasses—the North Island, and the South Island —and around 600 smaller islands. New Zealand is situated some 2,000 kilometres (1,200 mi) east of Australia across the Tasman Sea and roughly 1,000 kilometres (600 mi) south of the Pacific island areas of New Caledonia, Fiji, and Tonga. Because of its remoteness, it was one of the last lands to be settled by humans. During its long period of isolation, New Zealand developed a distinct biodiversity of animal, fungal, and plant life. The country's varied topography and its sharp mountain peaks, such as the Southern Alps, owe much to the tectonic uplift of land and volcanic eruptions. New Zealand's capital city is Wellington, while its most populous city is Auckland.

Labellum (botany)

In botany, the labellum is the part of the flower of an orchid or Canna, or other less-known genera that serves to attract insects, which pollinate the flower, and acts as a landing platform for them.

Contents

Description

Pterostylis irsoniana is a terrestrial, perennial, deciduous, herb with an underground tuber and three to five stem leaves increasing in size up to stem where the largest leaf is up to 180 mm (7 in) long and 12 mm (0.5 in) wide. The leaves are linear to lance-shaped, green with a reddish tinge and the uppermost leaf is taller than the flower. There is a single dark green flower with a reddish tinge near the tips borne on a flowering stem up to 350 mm (10 in) tall. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal is 15–30 mm (0.6–1 in) long and curves forward with a short-pointed tip. The lateral sepals are erect, in close contact with the galea with their tips spreading apart slightly from each other. The labellum is gently curved then suddenly curls downward at its tip with a dark red or blackish callus. Flowering occurs from October to January. [2] [3]

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

Pterostylis irsoniana was first formally described in 1950 by Edwin Hatch from a specimen collected at 1,160 m (3,810 ft) in the Egmont National Park. The description was published in Transactions and Proceedings of the Royal Society of New Zealand . [1] [4] The specific epithet (irsoniana) is a derived from the names of J. Bruce Irwin and O.E. Gibson "who between them have done much to elucidate the orchid flora of Mount Egmont". [4]

Egmont National Park national park

Egmont National Park is located south of New Plymouth, close to the west coast of the North Island of New Zealand. It is named after the mountain which dominates its environs, which itself was named by Captain Cook after John Perceval, 2nd Earl of Egmont, the First Lord of the Admiralty who promoted Cook's first voyage. Taranaki has been the Māori name for the mountain for many centuries, and the mountain itself now has two alternative official names, "Mount Taranaki" and "Mount Egmont".

The Transactions and Proceedings of the Royal Society of New Zealand was a scientific journal and magazine published by the Royal Society of New Zealand. Before 1933 the society was called the New Zealand Institute, and the journal's name was Transactions and Proceedings of the New Zealand Institute. It was active between 1868 and 1961 and was the most important scientific journal in New Zealand.

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

This greenhood grows in grass and montane forests of Nothofagus and subalpine Podocarpus scrub, often in deep leaf litter or on the edge of bogs. In the North Island it occurs from East Cape to Wellington and in the South Island on the western side as far south as Haast. [2] [3]

Montane ecosystems ecosystems found in mountains

Montane ecosystems refers to any ecosystem found in mountains. These ecosystems are strongly affected by climate, which gets colder as elevation increases. They are stratified according to elevation. Dense forests are common at moderate elevations. However, as the elevation increases, the climate becomes harsher, and the plant community transitions to grasslands or tundra.

<i>Nothofagus</i> genus of plants

Nothofagus, also known as the southern beeches, is a genus of 43 species of trees and shrubs native to the Southern Hemisphere in southern South America and Australasia. The species are ecological dominants in many temperate forests in these regions. Some species are reportedly naturalised in Germany and Great Britain. The genus has a rich fossil record of leaves, cupules and pollen, with fossils extending into the late Cretaceous period and occurring in Australia, New Zealand, Antarctica and South America. In the past, they were included in the family Fagaceae, but genetic tests revealed them to be genetically distinct, and they are now included in their own family, the Nothofagaceae.

<i>Podocarpus</i> genus of plants

Podocarpus is a genus of conifers, the most numerous and widely distributed of the podocarp family, Podocarpaceae. Podocarpus are evergreen shrubs or trees, usually from 1 to 25 metres tall, known to reach 40 metres (130 ft) at times. The cones have two to five fused cone scales which form a fleshy, berry-like, brightly coloured receptacle at maturity. The fleshy cones attract birds which then eat the cones and disperse the seeds in their droppings. There are approximately 97 to 107 species in the genus depending on the circumscription of the species.

Related Research Articles

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

Pterostylis coccina, commonly known as the scarlet greenhood, is a species of orchid endemic to eastern Australia. 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 spike. In this species, the rosette leaves are relatively large and dark green, and the flowers are white, and bluish-green or red. It grows in New South Wales and north-eastern Victoria.

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

Pterostylis banksii, commonly known as greenhood or tutukiwi, is a species of orchid endemic to New Zealand. Non-flowering plants have a rosette of leaves. Flowering plants have leaves on the flowering stem, some of which reach above the single relatively large, green flower with translucent white stripes. It is the most common, widespread and largest New Zealand greenhood and is found on both of the main islands.

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

Pterostylis fischii, commonly known as Fisch's greenhood, is a species of orchid endemic to south-eastern Australia. 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 spike. This greenhood has tawny-coloured flowers, a dorsal sepal with a long thread-like tip and a labellum which is hidden inside the flower.

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

Pterostylis atrans, commonly known as the dark-tip greenhood or blunt-tongue greenhood, is a species of orchid endemic to south-eastern Australia. As with similar greenhoods, plants in flower differ from those that are not flowering. The non-flowering plants have a rosette of leaves flat on the ground, but the plants in flower have a single flower with leaves on the flowering spike. In this species, the flower is green and reddish brown with a protruding sinus and small club-like tips on the ends of the lateral sepals.

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

Pterostylis revoluta, commonly known as the autumn greenhood, is a species of orchid endemic to south-eastern Australia. 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 spike. This greenhood has white and green flowers which have a long, curved, pointed labellum which extends beyond the sinus between the lateral sepals.

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

Pterostylis robusta, commonly known as the sharp-leaf greenhood, is a species of orchid endemic to south-eastern 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 have a single flower with leaves on the flowering spike. This greenhood has a relatively large green, white and reddish-brown flower with reddish-brown stripes with the labellum just visible inside the flower.

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

Pterostylis scabrida, commonly known as the rough greenhood, is a species of orchid endemic to Tasmania. It has a rosette of leaves at the base of the plant and a single green and white flower on a rough stem. It is widespread and common in wet forests and is one of the few species of Pterostylis to grow in rainforest.

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

Pterostylis longipetala, commonly known as the curved greenhood, is a species of orchid endemic to eastern Australia. 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 spike. This greenhood has dark green, brown and white flowers which lean slightly forwards and have sharply-pointed petals and a long, curved labellum.

Pterostylis agathicola, commonly known as the kauri greenhood, is a species of orchid endemic to the North Island of New Zealand. 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 spike. It grows almost exclusively in kauri forest and has a relatively large green and transparent white flower.

Pterostylis auriculata is a species of orchid endemic to New Zealand. Unlike many other greenhood orchids, this species lacks a rosette of leaves but instead only has leaves on the flowering stem. All parts of the plant are glossy and there is a single green flower with a reddish tinge.

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

Pterostylis australis, commonly known as the southern greenhood, is a species of orchid endemic to New Zealand. Unlike many other greenhood orchids, this species lacks a rosette of leaves but instead only has leaves on the flowering stem. The leaf's shape differs according to it position on the stem and there is a single green and white-striped flower. This greenhood occurs on both of the main islands of New Zealand and often forms large colonies.

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 cardiostigma is a species of orchid endemic to New Zealand. It has erect leaves, the upper leaves higher than the flower which is stiff, upright and green with narrow white stripes and pinkish tips. It barely opens fully and is sometimes mistaken for an unopened flower of Pterostylis banksii with which it often grows.

Pterostylis cernua, commonly known as the Westland greenhood, is a species of orchid endemic to New Zealand. Non-flowering plants have a rosette of leaves but flowering plants have a single white, dark green and reddish-brown flower with leaves on the flowering stem.

Pterostylis humilis is a species of orchid endemic to New Zealand. It has a rosette of leaves at the base of the plant and when flowering stem, leaves which usually obscure the dark green and white flower.

Pterostylis micromega, commonly known as the swamp greenhood, is a species of greenhood orchid endemic to New Zealand. Both flowering and non-flowering plants have a rosette of leaves while flowering plants also have a single, relatively large whitish flower with a pointed dorsal sepal. The flower colour and pointed dorsal sepal are unique in New Zealand Pterostylis.

Pterostylis montana is a species of greenhood orchid endemic to New Zealand. Flowering plants have erect, linear leaves on the flowering stem with a single green flower with translucent white stripes and an unusual twisted labellum.

Pterostylis oliveri is a species of greenhood orchid endemic to New Zealand. Flowering have plants spreading leaves on the flowering stem and a single green and white flower with a strongly down-curved dorsal sepal and long, tapering lateral sepals.

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

Pterostylis reflexa, commonly known as the dainty 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 relatively large white, green and light brown flower with a long, curved dorsal sepal and a protruding labellum.

Pterostylis rogersii, commonly known as the curled-tongue shell orchid, is a species of orchid endemic to the south-west of Western 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 and have a single flower with leaves on the flowering spike. This greenhood usually has a white and reddish-brown striped flower with a long, curved labellum and is found along the south coast between Binningup and Esperance.

References

  1. 1 2 "Pterostylis irsoniana". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. 1 2 de Lange, Peter James. "Pterostylis irsoniana". New Zealand Plant Conservation Network. Retrieved 30 June 2017.
  3. 1 2 "Pterostylis irsoniana". New Zealand Native Orchid Group. Retrieved 19 June 2017.
  4. 1 2 Hatch, Edwin Daniel (1950). "The epiphytic orchids of New Zealand and a new species of Pterostylis from Mount Egmont" (PDF). Transactions and Proceedings of the Royal Society of New Zealand. 78: 104–105. Retrieved 30 June 2017.