''Pterostylis depauperata'', commonly known as the keeled 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 ...

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

. 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

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 ...

s on the flower have relatively long, thread-like tips.

Description

''Pterostylis depauperata'' 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 which often grows in colonies. Non-flowering plants have a rosette of between three and seven egg-shaped, greyish green leaves lying flat on the ground. Each leaf is long and wide. Flowering plants have a single flower long and wide on a flowering stem high with a few small stem leaves. The flowers are white with pale green striations. 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 ...

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 has a thread-like tip long and

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 thread-like tips long. The labellum is long, about wide, dark brown and curved, and just protrudes above the sinus. Flowering occurs from March to August.

Taxonomy and naming

''Pterostylis depauperata'' was first formally described in 1943 by Frederick Bailey from a specimen collected near

Cairns Cairns (, ) is a city in Queensland, Australia, on the tropical north east coast of Far North Queensland. The population in June 2019 was 153,952, having grown on average 1.02% annually over the preceding five years. The city is the 5th-most-p ...

. The description was published in the ''Botany Bulletin'' of the Queensland Department of Agriculture.

Distribution and habitat

The keeled greenhood grows with grasses and small shrubs in woodland and forest between

Cooktown Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the Endeavour, for repairs ...

and

Ravenshoe Ravenshoe ( ) is a rural town and locality in the Tablelands Region, Queensland, Australia. In the , Ravenshoe had a population of 1,400 people. Geography Ravenshoe is on the Atherton Tableland in Far North Queensland. It is located south w ...

at altitudes above .

References

{{Taxonbar, from=Q15499827 depauperata Endemic orchids of Australia Orchids of New South Wales Plants described in 1891