''Pterostylis alobula'', commonly known as the winter greenhood, 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 ...

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 ...

. 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.

Description

''Pterostylis alobula'' is a terrestrial,

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () 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, aft ...

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 Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing ...

and when not flowering, a rosette of mostly egg-shaped leaves, long and long with a stalk up to long. Flowering plants usually have a single pale green flower with white stripes high borne on a flowering stem up to high with between two and six linear to lance-shaped stem leaves long and wide. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

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 ...

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. ...

with its tip usually horizontal. The

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

sepals are erect, held closely against the galea and have a broad V-shaped

sinus Sinus may refer to: Anatomy * Sinus (anatomy), a sac or cavity in any organ or tissue ** Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including: *** Maxillary sinus, is the largest of the paranasal sinuses, ...

between their bases. The labellum is red, curved and projects above the sinus. Flowering occurs from March to October.

Taxonomy and naming

The winter greenhood was first formally described in 1968 by

Edwin Hatch Edwin Warren Hatch (4 September 1835 Derby, England – 10 November 1889 Oxford, England) was an English theologian. He is best known as the author of the book '' Influence of Greek Ideas and Usages Upon the Christian Church'', which was based ...

and given the name ''Pterostylis trullifolia'' var. ''alobula''. The description was published in ''

Transactions and Proceedings of the Royal Society of New Zealand 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 ...

''. In 1968 it was raised to species status by Lucy Moore. 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 ...

(''alobula'') is derived from the

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 ''lobus'' meaning "an elongated projection or protuberance", "capsule" or "pod" with the

prefix A prefix is an affix which is placed before the Word stem, stem of a word. Adding it to the beginning of one word changes it into another word. For example, when the prefix ''un-'' is added to the word ''happy'', it creates the word ''unhappy'' ...

''a-'' meaning "without".

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.

References

{{Taxonbar, from=Q15492446 alobula Endemic orchids of Australia Orchids of New Zealand Plants described in 1968