Pterostylis alobula

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Winter greenhood
Orchids on Rangitoto.jpg
Pterostylis alobula on Rangitoto Island
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. alobula
Binomial name
Pterostylis alobula
Synonyms [1]

Pterostylis alobula, commonly known as the winter greenhood, is a species of orchid endemic to 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. This greenhood has pale green and white-striped flowers, similar to those of another New Zealand greenhood, P. trullifolia but are larger and paler in colour.

Contents

Description

Pterostylis alobula is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of mostly egg-shaped leaves, 5–15 millimetres (0.2–0.6 in) long and 4–15 millimetres (0.2–0.6 in) long with a stalk up to 10 millimetres (0.4 in) long. Flowering plants usually have a single pale green flower with white stripes 10–20 millimetres (0.4–0.8 in) high borne on a flowering stem up to 150 millimetres (6 in) high with between two and six linear to lance-shaped stem leaves 5–25 millimetres (0.2–1 in) long and 3–6 millimetres (0.1–0.2 in) wide. The dorsal sepal and petals are fused, forming a hood or "galea" over the column with its tip usually horizontal. The lateral sepals are erect, held closely against the galea and have a broad V-shaped sinus between their bases. The labellum is red, curved and projects above the sinus. Flowering occurs from March to October. [2] [3]

Taxonomy and naming

The winter greenhood was first formally described in 1968 by Edwin Hatch and given the name Pterostylis trullifolia var. alobula. The description was published in Transactions and Proceedings of the Royal Society of New Zealand . [4] In 1968 it was raised to species status by Lucy Moore. [1] The specific epithet (alobula) is derived from the Latin word lobus meaning "an elongated projection or protuberance", "capsule" or "pod" [5] :634 with the prefix a- meaning "without". [5] :62

Distribution and habitat

The winter greenhood usually grows in sparse leaf litter under shrubs in forest but sometimes also in scrub or pasture. It occurs on both main islands of New Zealand and on some of the offshore islands. [2] [3]

Related Research Articles

<i>Pterostylis trullifolia</i>

Pterostylis trullifolia, commonly known as the trowel-leaved greenhood, is an orchid species endemic to New Zealand. As with similar orchids, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of wrinkled, trowel-shaped leaves but the flowering plants have a single flower with a bulging, platform-like sinus between the lateral sepals and leaves on the flowering spike.

<i>Pterostylis banksii</i>

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 decurva</i>

Pterostylis decurva, commonly known as the summer 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 but the flowering plants have a single flower with leaves on the flowering spike. This greenhood usually flowers in summer and has a white flower with green stripes and a brownish tinge. It is similar to P. aestiva but has paler green flowers.

<i>Pterostylis foliata</i>

Pterostylis foliata, commonly known as the slender greenhood, is a species of orchid widespread in south-eastern Australia and New Zealand. Flowering plants have a rosette of three to six, dark green, crinkled leaves crowded around the flowering stem and a single dark green and brown flower with a deep V-shaped sinus between the lateral sepals.

<i>Pterostylis revoluta</i>

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.

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.

<i>Pterostylis amabilis</i>

Pterostylis amabilis is a species of orchid endemic to 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 lack a rosette at the base but have up to ten tiny white and red to reddish-brown flowers. It is similar to P. parviflora but has larger rosette leaves and larger, more brightly coloured flowers.

Pterostylis areolata is a species of orchid endemic to 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. This greenhood has green and translucent white-striped flowers similar to those of P. australis but the stem leaves are shorter and never higher than the flowers.

<i>Pterostylis brumalis</i>

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.

<i>Pterostylis depauperata</i>

Pterostylis depauperata, commonly known as the keeled greenhood, is a species of orchid endemic to Queensland. Flowering plants have a rosette of leaves at the base of a flowering stem with a single small white flower with pale green marks, and a few small stem leaves. Non-flowering plants only have a rosette of leaves. All three sepals on the flower have relatively long, thread-like tips.

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.

<i>Pterostylis irsoniana</i>

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.

Pterostylis irwinii is a species of greenhood orchid endemic to New Zealand. Flowering plants have erect, linear leaves on the flowering stem while non-flowering plants have a rosette of egg-shaped leaves. There is a single green flower with translucent white stripes and reddish-brown tips.

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 paludosa, commonly known as swamp greenhood, is a species of greenhood orchid endemic to New Zealand. As with similar orchids, plants in flower differ from those that are not. Those not in flower have a rosette of leaves on a short stalk but plants in flower lack a rosette and have a single flower with leaves on the flowering spike. This greenhood has a translucent white flower with pale to yellowish-green stripes.

<i>Pterostylis reflexa</i>

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 scoliosa, commonly known as the small kinked greenhood, is a species of orchid endemic to Queensland. 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, pale green and pale brown flower with a kinked or curved labellum protruding above the sinus between the lateral sepals.

Pterostylis tristis, commonly known as the midget greenhood, is a species of greenhood orchid endemic to New Zealand. Both flowering and non-flowering plants have a rosette of fleshy leaves lying flat on the ground and flowering plants have up to eight yellowish-green or brownish flowers with pale stripes.

Pterostylis venosa, commonly known as a greenhood, is a species of orchid endemic to New Zealand and which usually grows in colonies. Both flowering and non-flowering plants have a rosette of erect to spreading leaves, and flowering plants have a single yellowish-green to dark green flower with white stripes. It is similar to P. humilis.

Pterostylis divaricata is a species of orchid endemic to northern New South Wales. It grows in colonies of genetically identical plants. As with similar orchids, plants in flower differ from those that are not. Those not in flower have a rosette of leaves that lie flat on the ground. Plants in flower lack a rosette at the base but have up to ten translucent white flowers with green and brown stripes. This greenhood is similar to P. striata but has larger flowers and a longer tip on the dorsal sepal.

References

  1. 1 2 3 "Pterostylis alobula". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. 1 2 "Pterostylis alobula". New Zealand Plant Conservation Network. Retrieved 13 June 2017.
  3. 1 2 "Pterostylis alobula". New Zealand Native Orchid Group. Retrieved 13 June 2017.
  4. Hatch, Edwin (1949). "New Zealand forms of Pterostylis". Transactions and Proceedings of the Royal Society of New Zealand. 77: 244. Retrieved 13 June 2017.
  5. 1 2 Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.