''Genoplesium nigricans'', commonly known as mallee midge orchid, is a species of orchid endemic to

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It is a terrestrial

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 a single leaf mostly surrounding the stem, and up to 50 tiny, greenish flowers with a deep maroon-coloured labellum and often have a fruity fragrance. Australian authorities use the name ''Corunastylis tepperi'', a widespread species which has been confused with '' Corunastylis nigricans'', a species with purplish brown flowers and which only occurs on Kangaroo Island and the Eyre Peninsula.

Description

''Genoplesium nigricans'' is a terrestrial, perennial, deciduous, sympodial

. A single long leaf surrounds the stem from the base of the plant to the lowest of the flowers. The leaf is long and wide. The inflorescence is a spike with from 5 to 50 crowded, tiny, non-

resupinate Resupination is derived from the Latin word ''resupinus'', meaning "bent back with the face upward" or "on the back". "Resupination" is the noun form of the adjective "resupine" which means "being upside-down, supine or facing upward". The word " ...

flowers which are bright green with a dark maroon-coloured to purplish-black labellum. Each flower is

pendulous This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

, about wide and long with

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 and sepals that do not spread widely. The dorsal sepal is a broad egg-shape, about long and wide. The two lateral sepals are lance-shaped, long and about wide and dished near their base. The petals are egg-shaped, about long and less than wide. The dark-coloured labellum is egg-shaped, about the same size as the petals with a minutely wavy edge. The callus is narrow egg-shaped and extends almost to the tip of the labellum. 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. ...

, which is below the labellum has wings with a rough surface. Flowering occurs between February and May and the fruit that follows is a non-fleshy,

dehiscent Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that op ...

capsule containing hundreds of seeds.

Taxonomy and naming

In 1880, Otto Temper, a South Australian school teacher, reported to the Royal Society of South Australia, the discovery he had made of an orchid "in respect of which Baron F. v. Mueller, has done me the honour of naming it ''Prasophyllum Tepperi''". Tepper's description was formalised by

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (german: Müller; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Vict ...

in 1882 with the name published in '' Systematic Census of Australian Plants''. In 2002, David Jones and Mark Clements changed the name of ''Prasophyllum tepperi'' to ''Corunastylis tepperi''. The World Checklist of Selected Plant Families lists ''C. tepperi'' as a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''Genoplesium nigricans''. 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 ...

(''tepperi'') honours Otto Tepper and the epithet ''nigricans'' is a Latin word meaning "blackish". '' Corunastylis nigricans'', a different species, sometimes confused with ''Genoplesium nigricans'' or ''Corunastylis tepperi'', has purplish brown flowers with green markings and a shiny, dark purplish labellum and only occurs in parts of South Australia.

Distribution and habitat

The mallee midge orchid occurs in arid areas of north-western Victoria, mostly in mallee

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...

and ''

Callitris ''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. p ...

'' woodland, and in the Avon Wheatbelt, Coolgardie, Esperance Plains, Hampton and Mallee

biogeographic regions A biogeographic realm or ecozone is the broadest biogeographic division of Earth's land surface, based on distributional patterns of terrestrial organisms. They are subdivided into bioregions, which are further subdivided into ecoregions. De ...

of southern Western Australia. There are also isolated populations in South Australia. It is a very drought and heat tolerant species which is dormant when the soil is hard-packed and dry, growing and flowering in the cooler, wetter autumn months.

Ecology

This species appears to be pollinated by tiny fruit flies which are attracted by the scent of the flower at the same time as other plants, such as ''

Leucopogon ''Leucopogon'' is a genus of about 150-160 species of shrubs or small trees in the family Ericaceae, in the section of that family formerly treated as the separate family Epacridaceae. They are native to Australia, New Zealand, New Caledonia, the ...

'' are flowering.

References

External links

* * {{Taxonbar, from=Q15463536 nigricans Orchids of Australia Flora of Western Australia Plants described in 1880