''Genoplesium'' commonly known as midge orchids, is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of about 50 species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

s in the orchid family,

Orchidaceae Orchids are plants that belong to the family (biology), family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan distribution, cosmopolitan plants that ...

and is found in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

. Midge orchids are terrestrial herbs with a single leaf at the base of the plant. They are similar to orchids in the genus ''

Prasophyllum ''Prasophyllum'', commonly known as leek orchids, is a genus of about 140 species of flowering plants in the orchid family, Orchidaceae and is found in Australia and New Zealand. The Australian species are found in all states but have not been re ...

'' in that plants without flowers have a hollow, onion-like leaf. The flowers are small but often scented and attractive to their insect pollinators. There is disagreement about which species belong to this genus and some taxonomists suggest that most belong in the genus '' Corunastylis''.

Description

Orchids in the genus ''Genoplesium'' are terrestrial,

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

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 Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

sympodial In botany, sympodial growth is a bifurcating branching pattern where one branch develops more strongly than the other, resulting in the stronger branches forming the primary shoot and the weaker branches appearing laterally. A sympodium, als ...

herbs, usually with a few inconspicuous, fine roots and a pair of more or less spherical

tuber Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reproduc ...

s. The tubers are partly covered by a protective fibrous sheath which extends to the soil surface. Replacement tubers form at the end of short root-like

stolon In biology, a stolon ( from Latin ''wikt:stolo, stolō'', genitive ''stolōnis'' – "branch"), also known as a runner, is a horizontal connection between parts of an organism. It may be part of the organism, or of its skeleton. Typically, animal ...

s. Orchids in this genus do not reproduce using "daughter" tubers, but rely on their flowers for reproduction. A single long, cylindrical,

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

leaf develops near the base of the plant and is fused to the flowering stem. The leaf of flowering plants is solid but those of sterile plants are hollow. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a spike or

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

with a few to many non- resupinate flowers which are often have reddish brown or purple parts and often smell fruity. 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 The fus ...

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 Etymology The term ''sepalum'' ...

is usually shorter and wider than two

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

sepals, dished on the lower surface and often forms a hood 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

sepals are often joined near their bases and the lateral

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s are shorter and narrower than the sepals. As is usual in orchids, one

is highly modified as the central labellum, much different from the other petals and sepals. The labellum is above the column and joined to it by a flexible attachment, so that the labellum vibrates in a breeze. The edge of the labellum sometimes has fine teeth,

glands A gland is a Cell (biology), cell or an Organ (biology), organ in an animal's body that produces and secretes different substances that the organism needs, either into the bloodstream or into a body cavity or outer surface. A gland may also funct ...

or hairs. The labellum has a

callus A callus (: calluses) is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, b ...

which consists often covers its surface and which consists of a raised, fleshy plate. The sexual parts of the flower are fused to the column which is short and has narrow wings, often with an extension at the front. Midge orchids usually flower in summer, autumn or winter, depending on species, and the fruit that follows flowering 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 up to 500 seeds.

Taxonomy and naming

The genus ''Genoplesium'' was first formally described by

Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and author Entertainers and artists * Washboard Sam or Robert Brown (1910–1966), American musician and singer * Robert W. Brown (1917–2009), American printmaker ...

in 1810 and the description was published in ''

Prodromus Florae Novae Hollandiae ''Prodromus Florae Novae Hollandiae et Insulae Van Diemen'' (Prodromus of the Flora of New Holland and Van Diemen's Land) is a book by the botanist Robert Brown Robert Brown may refer to: Robert Brown (born 1965), British Director, Animator and ...

''. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

is '' G. baueri''. The name ''Genoplesium'' is derived from the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

words ''genos'' meaning "race", "stock" or "kind" and ''plesios'' meaning "near" referring to the similarity of these orchids to those in the genus ''

''. David Jones and Mark Clements proposed moving all but one species of ''Genoplesium'' to '' Corunastylis''. The change has been accepted by the Royal Botanic Gardens Victoria who list twelve species of '' Corunastylis'' but not

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

Distribution and habitat

Midge orchids mainly occur in

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, Victoria,

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

and

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

. There is one species ('' G. calopterum'') in

and two ('' G. nudum'' and '' G. pumilum'') in

. Most ''Genoplesium'' species occur in near-coastal regions but also grow in montane and sub-alpine areas. In Australia they are most common in moss beds over rock, in forest, woodland, heath and mallee. ''Genoplesium'' species in New Zealand grow in grassy places as well as in swamps and the New Caledonian species grows in stunted maquis.

Ecology

Some of the characteristics of the flowers of midge orchids, such as small size, dull colours and hairy parts waving in a breeze, suggest pollination by small flies. Some studies have suggested that the flowers are pollinated exclusively by flies of the Superfamily Chloropoidea (now in the Family '' Milichiidae''). A few species, such as the New Zealand '' G. nudum'' appear to exclusively self-pollinate.

Species list

The species recognised by the ''

'' as of July 2023 are: *'' Genoplesium acuminatum'' ( R.S.Rogers) D.L.Jones & M.A.Clem. ( NSW) – pointed midge orchid *'' Genoplesium alticola'' D.L.Jones & B.Gray ( Qld) – tableland midge orchid *'' Genoplesium anthracinum'' (D.L.Jones) J.M.H. Shaw (NSW) – black midge orchid *'' Genoplesium apostasioides'' (Fitzg.) D.L.Jones & M.A.Clem. (NSW) – freak midge orchid *'' Genoplesium archeri'' (Hook.f.) D.L.Jones & M.A.Clem. ( Vic, Tas, NSW, Qld) - elfin midge orchid *'' Genoplesium arrectum'' D.L.Jones (Vic, NSW, ACT) – erect midge orchid *'' Genoplesium baueri'' R.Br. (NSW) – brittle midge orchid, yellow gnat orchid *'' Genoplesium bishopii'' D.L.Jones (NSW) – Gibraltar Range midge orchid *'' Genoplesium brachystachyum'' ( Lindl.) D.L.Jones & M.A.Clem. (Tas) – short spike midge orchid *'' Genoplesium branwhiteorum'' M.A.M.Renner & P.H.Weston (N.S.W.) *'' Genoplesium calopterum'' ( Rchb.f.) D.L.Jones & M.A.Clem. (

) *'' Genoplesium capparinum'' (D.L.Jones & L.M.Copel.) J.M.H.Shaw (Vic.) *'' Genoplesium carectum'' (D.L.Jones & J.M.H.Shaw. (N.S.W.) *'' Genoplesium citriodorum'' D.L.Jones & M.A.Clem. (NSW) – lemon-scented midge orchid *'' Genoplesium clivicola'' (D.L.Jones) J.M.H.Shaw (NSW, ACT) *'' Genoplesium confertum'' (D.L.Jones) D.L.Jones & M.A.Clem. (Qld) – crowded midge orchid *'' Genoplesium cornutum'' (D.L.Jones) J.M.H.Shaw (NSW, ACT) *'' Genoplesium cranei'' D.L.Jones (Qld) – Blackall Ridge midge orchid *'' Genoplesium cuspidatum'' (D.L.Jones & L.M.Copel.) J.M.H.Shaw (N.S.W., Qld.) *'' Genoplesium despectans'' (Hook.f.) D.L.Jones & M.A.Clem. ( SA, Vic, Tas, NSW) – sharp midge orchid *'' Genoplesium ectopum'' D.L.Jones (ACT) – Brindabella midge orchid *'' Genoplesium eriochilum'' (Fitzg.) D.L.Jones & M.A.Clem. (NSW) – Mount Wilson midge orchid *'' Genoplesium filiforme'' (Fitzg.) D.L.Jones & M.A.Clem. (NSW, Qld) – glandular midge orchid *'' Genoplesium fimbriatum'' (R.Br.) D.L.Jones & M.A.Clem. (NSW, Qld) – fringed midge orchid *'' Genoplesium firthii'' (L.Cady) D.L.Jones (Tas) – Firth's midge orchid *'' Genoplesium formosum'' D.L.Jones (NSW) – Cathcart midge orchid *'' Genoplesium geminatum'' M.A.M.Renner & Towle (NSW) *'' Genoplesium insigne'' D.L.Jones (NSW) – dark midge orchid *'' Genoplesium laminatum'' (Fitzg.) M.A.M.Renner (NSW) *'' Genoplesium leptochilum'' (D.L.Jones) J.M.H.Shaw (Vic) *'' Genoplesium littorale'' D.L.Jones (NSW) – Tuncurry midge orchid *'' Genoplesium morinum'' D.L.Jones (Vic, NSW) – mulberry midge orchid *'' Genoplesium morrisii'' (Nicholls) D.L.Jones & M.A.Clem. (SA, Vic, Tas, NSW) – bearded midge-orchid *'' Genoplesium mucronatum'' (Rupp) M.A.M.Renner (NSW) *'' Genoplesium nigricans'' (R.Br.) D.L.Jones & M.A.Clem. (SA) – mallee midge-orchid *'' Genoplesium nudiscapum'' (Hook.f.) D.L.Jones & M.A.Clem. (Tas) – dense midge-orchid *'' Genoplesium nudum'' (Hook.f.) D.L.Jones & M.A.Clem. ( NZ, Vic, Tas, NSW, ACT) – tiny midge orchid *'' Genoplesium oliganthum'' D.L.Jones (NSW) – Mongarlowe midge orchid *'' Genoplesium ostrinum'' D.L.Jones (NSW) – purple midge orchid *'' Genoplesium parvicallum'' ( Rupp) D.L.Jones & M.A.Clem. (Qld) – mountain-top midge orchid *'' Genoplesium pedersonii'' D.L.Jones (Qld) – Pederson's midge orchid *'' Genoplesium plumosum'' (Rupp) D.L.Jones & M.A.Clem. (NSW) – Tallong midge orchid or plumed midge orchid *'' Genoplesium psammophilum'' D.L.Jones (Qld) – coastal midge orchid *'' Genoplesium pumilum'' (Hook.f.) D.L.Jones & M.A.Clem. (NZ, Vic, Tas, NSW, Qld) – green midge orchid *'' Genoplesium rhyoliticum'' D.L.Jones & M.A.Clem. (NSW) – Pambula midge orchid *'' Genoplesium rufum'' (R.Br.) D.L.Jones & M.A.Clem. (NSW, Qld) – rufous midge orchid *'' Genoplesium ruppii'' (R.S.Rogers) D.L.Jones & M.A.Clem. (NSW) – Rupp's midge orchid *'' Genoplesium sagittiferum'' (Rupp) D.L.Jones & M.A.Clem. (NSW) – horned midge orchid *'' Genoplesium sigmoideum'' D.L.Jones (Qld) – Dave's Creek midge orchid *'' Genoplesium simulans'' D.L.Jones (NSW) – Blue Mountains midge orchid *'' Genoplesium stephensonii'' (D.L.Jones) J.M.H.Shaw (NSW) *'' Genoplesium superbum'' D.L.Jones (NSW) – pink midge orchid *'' Genoplesium systenum'' D.L.Jones (NSW) – Kangarooby midge orchid *'' Genoplesium tasmanicum'' D.L.Jones (Tas) – Tasmanian midge orchid *'' Genoplesium tectum'' D.L.Jones (Qld) – Cardwell midge orchid *'' Genoplesium tenellum'' (D.L.Jones & L.M.Copel.) J.M.H.Shaw (NSW) *'' Genoplesium trifidum'' (Rupp} M.A.M.Renner (NSW) *'' Genoplesium turfosum'' D.L.Jones (NSW) – alpine midge orchid *'' Genoplesium validum'' D.L.Jones (Qld) – Blackdown midge orchid *'' Genoplesium vernale'' D.L.Jones (NSW) – spring midge orchid *'' Genoplesium woollsii'' (F.Muell.) D.L.Jones & M.A.Clem. (NSW) – dark midge orchid

References

External links

* {{Taxonbar, from=Q1309069 Diurideae genera