''Prasophyllum'', commonly known as leek 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 140 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 ...

and

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 ...

. The Australian species are found in all states but have not been recorded in the

Northern Territory The Northern Territory (abbreviated as NT; known formally as the Northern Territory of Australia and informally as the Territory) is an states and territories of Australia, Australian internal territory in the central and central-northern regi ...

. The common name arises from their having a hollow, leek- or onion-like leaf. Some species only flower after summer fires and have flowers similar to those of ''

Xanthorrhoea ''Xanthorrhoea'' () is a genus of about 30 species of Succulent plant, succulent flowering plants in the family Asphodelaceae. They are Endemism, endemic to Australia. Common names for the plants include grasstree, grass gum-tree (for resin-yie ...

'' which flower at the same time, suggesting that they employ the same pollinating insects. Leek orchids are similar to those in the genus ''

Genoplesium ''Genoplesium'' commonly known as midge orchids, is a genus of about 50 species of flowering plants in the orchid family, Orchidaceae and is found in Australia, New Zealand and New Caledonia. Midge orchids are terrestrial herbs with a single le ...

'' except that the free part of the leaf is cylindrical (flat in ''Genoplesium'') and the labellum has a solid (rather than flexible) connection to 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 ...

. They range in size from the little laughing leek orchid ('' P. gracile'') at about to the king leek orchid ('' P. regium'') which grows up to tall.

Description

Orchids in the genus ''Prasophyllum'' 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 Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnish (food), garnishing food, for medicinal purposes, or for fragrances. Culinary use typi ...

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 partly covered by a fibrous sheath. 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. Leek orchids rarely reproduce by forming "daughter" tubers, relying on their flowers for reproduction. A single onion or leek-like leaf develops near the base of the plant and accounts for the common name of the group. The leaf is long, narrow, hollow, cylindrical and

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, ...

. 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 breaking through a thin part of the leaf. 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 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 which are often joined. The petals are often curved, shorter and narrower than the sepals. As is usual in orchids, one

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 ...

is highly modified as the central labellum, differing markedly from the other petals and sepals. The labellum is positioned above the column and rigidly attached to its base. Its edges are usually wavy and rolled back. 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 of a raised, fleshy plate which is usually channelled, with the base forming an inverted basin shape. The sexual parts of the flower are fused to the

which is short and has narrow wings, often with a small lobe at the front. Leek orchids usually flower between late winter and early summer, 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 ''Prasophyllum'' 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 ...

''. Brown described twelve species but did not name a

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 ...

, however in 1989, Mark Clements nominated '' P. australe'' as the

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...

. The name ''Prasophyllum'' 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 ''prason'' meaning "leek" and ''phyllon'' meaning "leaf".

Species

Distribution and habitat

Leek orchids occur in all states of Australia, but not in the Northern Territory. There are 20 named species in

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

as well as a further 40 that have been discovered but not as yet described. There are 28 species in

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 ...

, about 40 in

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 ...

and 15 in

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 ...

has about 6 species, occurring on both main islands as well as Stewart and Chatham Islands. In Western Australia alone, they grow in a range of habitats from the margins of salt lakes, to swamps and dense karri (''

Eucalyptus diversicolor ''Eucalyptus diversicolor'', commonly known as karri, is a species of flowering plant in the family Myrtaceae and is endemic to the south-west of Western Australia. It is a tall tree with smooth light grey to cream-coloured, often mottled bar ...

'') forests.

Ecology

''Prasophyllum'' species are

mycotroph A mycotroph is a plant that gets all or part of its carbon, water, or nutrient supply through symbiotic association with fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes mic ...

ic, requiring

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

fungi for seed germination. The main fungus is '' Ceratobasidium cornigerum''. Many Western Australian species only flower after summer fires and in other years only produce leaves. Most flowers are strongly scented, produce nectar and are pollinated by insects but a few appear able to self-pollinated if not visited. They often have flowers similar to grass trees in the genus ''

'', flower under similar conditions and are visited by a similar range of insects, suggesting that they mimic grass tree flowers.

Species

As at October 2017, about 140 species are recognised by the

World Checklist of Selected Plant Families The World Checklist of Selected Plant Families (usually abbreviated to WCSP) was an "international collaborative programme that provides the latest peer reviewed and published opinions on the accepted scientific names and synonyms of selected p ...

. Eight species described in 2017 are not included on the Checklist yet but are included in the

International Plant Names Index The International Plant Names Index (IPNI) describes itself as "a database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes." Coverage of plant names is best at the rank of species and genus. It inclu ...

. They are ''P. crassum'', ''P. nitidum'', ''P. roseum'', ''P. rousei'', ''P. stygium'', ''P. sylvicola'', ''P. spadiceum'' and ''P. tortilis''.

Species list

See List of ''Prasophyllum'' species Image:Strettle Road Reserve prasophyllum elatum.jpg, ''

Prasophyllum elatum ''Prasophyllum elatum'', commonly known as the tall leek orchid, snake orchid or piano orchid, is a species of orchid in the family Orchidaceae which is endemic to Australia. It is one of the tallest orchids found in Western Australia as well as ...

'' at the Strettle Road Reserve Glen Forrest in Western Australia Image:Prasophyllum sargentii 02.jpg, '' Prasophyllum sargentii'' growing near Hopetoun Western Australia Image:Prasophyllum brevilabre.jpg, '' Prasophyllum brevilabre'' growing on Black Mountain in the Australian Capital Territory Image:Prasophyllum lindleyanum.jpg, '' Prasophyllum lindleyanum'' growing near

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

in Victoria Image:Prasophyllum sylvestre.jpg, ''

Prasophyllum sylvestre ''Prasophyllum sylvestre'', commonly known as the forest leek orchid, is a species of orchid endemic to south-eastern Australia. It has a single tubular, bright green leaf and up to thirty faintly scented, pale green, pink and reddish-brown flow ...

'' near the

Tuross River The Tuross River, an open semi-mature wave dominated barrier estuary or perennial stream, is located in the South Coast region of New South Wales, Australia. Course and features Tuross River rises of the eastern slopes of the Kybeyan Range, ...

in New South Wales Image:Prasophyllum montanum.jpg, '' Prasophyllum montanum'' in the

Namadgi National Park Namadgi National Park is a protected area in the southwest of the Australian Capital Territory (ACT), bordering Kosciuszko National Park in New South Wales. It lies approximately southwest of Canberra, and occupies approximately 46 percent of th ...

in the Australian Capital Territory

References

External links

*
West Australian orchids
{{Taxonbar, from=Q3308356 Diurideae genera Orchids of Australia Orchids of New Zealand