''Pterostylis divaricata'', commonly known as northern striped 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 ...

to northern

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 ...

. 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 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 c ...

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 ...

Description

''Pterostylis divaricata'' 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 five to nine dark green, broad egg-shaped leaves that lie flat on the ground. Each leaf is long and wide. Plants in flower usually have only one, long, borne on a thin, smooth flowering stem high. Three to five dark green stem leaves long and wide are arranged on the side of the flowering spike. The flowers are translucent white with green and brown stripes. The dorsal sepal 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. ...

. The dorsal sepal is long, wide and gradually tapers to a thread-like tip long. 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 with thread-like tips about long that are held high above the galea. The

s are oblong to lance-shaped, long, about wide and curved with flanges about wide. The

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 the bases of the lateral sepals bulges forward with a V-shaped notch in the centre. The labellum is white with a brown tip and curves forward slightly, just visible above the sinus. Flowering occurs from March to May.

Taxonomy and naming

This greenhood was first formally described in 2016 by David Jones and Lachlan Copeland and given the name ''Diplodium divaricatum''. The description was published in the ''Australian Orchid Review'' from a specimen collected on Mount Duval. In the same year, the same authorities changed the name to ''Pterostylis divaricata'' "to allow for the different taxonomic views held at generic level within the subtribe". 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 ...

(''divaricata'') 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 "spread apart", referring to the spread tips of the lateral sepals. This species has previously been known as ''Pterostylis'' sp. aff. ''alata''.

Distribution and habitat

''Pterostylis divaricata'' grows with grasses, ferns and shrubs in woodland and forest on the higher parts between the New England Tableland and

Mummel Gulf National Park Mummel Gulf is a national park located in New South Wales, Australia, approximately by road north of Sydney. It is situated approximately southeast of Walcha on the unsealed Enfield Forest Road and south of the Oxley Highway. The Mummel R ...

References

{{Taxonbar, from1=Q51885547, from2=Q51885555 divaricata Endemic orchids of Australia Orchids of New South Wales Plants described in 2016 Taxa named by David L. Jones (botanist)