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''Thelymitra'', commonly known as sun orchids, is a
genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of more than 100
species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...
of
plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...
s in the orchid
family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
,
Orchidaceae 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 ...
. Unlike most other orchids, sun orchids lack a highly modified labellum and all three
petal Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corolla''. Petals are usuall ...
s are similar in size, shape and colour. 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 ...
is, however, highly modified and usually has prominent wings or glands which are helpful in identifying the species. Most sun orchids close their flowers at night, in cloudy or cool weather, giving rise to their common name. The scientific name means "woman's hood" and refers to the hooded column present in most, but not all species. Most species are
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 els ...
to Australia although some are found as far from there as the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
and
Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
. The
type species In 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 species that contains the biological type specimen( ...
, '' Thelymitra longifolia'', the first to be formally described, was collected in
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...
.


Description

Orchids in the genus ''Thelymitra'' are 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, a ...
,
sympodial 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, also referred to a ...
herbs 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 medicina ...
usually with a few inconspicuous, fine roots and a pair of oval-shaped
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 growin ...
s. A single leaf emerges from near the base of the plant and surrounds the lower part of the flowering stem. The
inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...
is a
raceme A raceme ( or ) or racemoid is an unbranched, 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 produced as the sh ...
with from one to many
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 with 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 ...
s and three petals all more or less alike in size, shape and ornamentation. (The labellum is not highly modified as in most other orchid genera but is similar to the other two petals.) The sexual parts of the flower are fused 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 ...
which is short and stubby with wings which surround the column, forming a hood-like "mitra". 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 ...
part of the mitra is usually ornamented, with a flat midsection and two side arms. The lower part of the mitra forms an unornamented rim below the column. The flowers of most species only open in bright warm sunlight and close at night or during cold or cloudy weather. A few species self pollinate and their reaction to environmental change is not as apparent. 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 o ...
capsule containing up to 500 seeds.


Taxonomy and naming

Joseph Banks collected specimens of '' Thelymitra longifolia'' on the
North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-larges ...
of New Zealand during Cook's first expedition to the
South Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
but the first formal description of that species was made by Johann Forster and his son
Georg Georg may refer to: * ''Georg'' (film), 1997 * Georg (musical), Estonian musical * Georg (given name) * Georg (surname) George is a surname of Irish, English, Welsh, South Indian Christian, Middle Eastern Christian (usually Lebanese), French, o ...
during Cook's second expedition to Australia. They made their collections on the
South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasma ...
of New Zealand. ''Thelymitra longifolia'' is therefore the
type species In 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 species that contains the biological type specimen( ...
. In 1803, Robert Brown collected '' T. venosa'' from
Port Jackson Port Jackson, consisting of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta Rivers, is the ria or natural harbour of Sydney, New South Wales, Australia. The harbour is an inlet of the Tasman ...
and was the first to formally describe it in 1810. The name "''Thelymitra''" is derived from the
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
words ''thelys'' meaning "belonging to women" and ''mitra'' meaning "headdress" or "turban" referring to the hooded column.


Distribution and habitat

There are about 100 species distributed in higher rainfall areas of Australia, 15 in
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 List of islands of New Zealand, smaller islands. It is the ...
, 11 of which are
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 els ...
, one in New Caledonia, one in
East Timor East Timor (), also known as Timor-Leste (), officially the Democratic Republic of Timor-Leste, is an island country in Southeast Asia. It comprises the eastern half of the island of Timor, the exclave of Oecusse on the island's north-we ...
and one in
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...
and the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
. Australian species grow in a range of habitats from swamps to relatively dry sandplains. They are common around
granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies und ...
boulders where they benefit from runoff. The New Zealand species grow in boggy places and on clay banks and '' T. javanica'' grows on sparsely vegetated mountain slopes.


Ecology

The particular shape and color of the sun orchids mimics the flowers of lily family (Liliaceae) and the family Goodeniaceae, aiming by deceit for the same insect pollinators. The slender sun orchid ('' T. pauciflora'') only opens for a short time (or not at all) and is self-pollinating. This self-pollination is a successful strategy followed by several other species such as and '' T. circumsepta'', '' T. graminea '', '' T. holmesii'' and '' T. mucida''.


Conservation

Several species are considered by the IUCN as endangered ('' T. epipactoides'') or critically endangered ('' T. gregaria'', '' T. hiemalis'' and '' T. × mackibbinii'').


Use in horticulture

Thelymitras can be grown in a freely draining, dense mixture with partially composted organic matter. A suitable mixture is an equal mix of 7 mm road screenings, year old composted wood chips and commercial potting mix. It is good practice to cover the surface in pine or she-oak needles to control water loss and to feed the mycorrhizal fungi that support the orchid. Due to the buds only opening in warm weather, it is common practice to induce flowering by using a bank of strong incandescent lights to simulate the warm sun. Some work has gone into growing hybrids for better growing and more colour.


Species

See List of ''Thelymitra'' species


Gallery

Image:Thelymitra.PLateI.jpg, Several Thelymitra species :2, 3, 6, 7, 8, 9 Image:Thelymitra cyanea LC0261.jpg, Swamp sun orchid (''
Thelymitra cyanea ''Thelymitra cyanea'', commonly known as the veined sun orchid in Australia and as the swamp sun orchid or striped sun orchid in New Zealand, is a species of orchid which is Indigenous (ecology), native to New Zealand and south-eastern Australia ...
'') Image:LR077 72dpi Thelymitra sp.jpg, ''Thelymitra'' species by Lewis Roberts. Image:ThelymitraCampanulata.jpg, Bell orchid (''
Thelymitra campanulata ''Thelymitra campanulata'', commonly called the bell sun orchid or shirt orchid, is a species of orchid in the family Orchidaceae and is endemic to the south-west of Western Australia. It is a common species with a single narrow leaf and up to fi ...
'') Image:Thelymitra antennifera.JPG, ''
Thelymitra antennifera ''Thelymitra antennifera'', commonly called the rabbit-eared sun orchid, lemon-scented sun orchid or vanilla orchid is a species of orchid which is native to Western Australia, South Australia and Victoria and northern parts of Tasmania. ''The ...
'' in the
Stirling Range National Park Stirling Range National Park is a national park in the Great Southern region of Western Australia, approximately south-east of Perth. Description It protects the Stirling Ranges, or Koikyennuruff, a range of mountains and hills over wide fr ...
Image:Jarrahdale Flower 2.jpg, '' Thelymitra crinita'' near Jarrahdale Image:Thelymitra rubra (24879748272).jpg, ''
Thelymitra rubra ''Thelymitra rubra'', commonly called the salmon sun orchid or pink sun orchid, is a species of orchid endemic to southeastern Australia. It has a single thin, grass-like leaf and up to five salmon pink flowers with broad, toothed arms on the s ...
'' Image:Dotted Sun Orchid (6115788560).jpg, ''
Thelymitra ixioides ''Thelymitra ixioides'', known as the spotted sun orchid or dotted sun orchid, is a species of orchid that is Indigenous (ecology), native to southern and eastern Australia and to New Zealand. It has a single long, thin, dark green leaf and up ...
'' in the
Royal National Park The Royal National Park is a protected national park that is located in Sutherland Shire in the Australian state of New South Wales, just south of Sydney. The national park is about south of the Sydney central business district near the l ...


References

* * (in German)


External links

* {{Taxonbar, from=Q3299954 Diurideae genera