Pterostylis

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Pterostylis
Flower of Pterostylis curta, type species of the genus

Flower of Pterostylis curta , type species of the genus

Systematics
Order : Asparagales (Asparagales)
Family : Orchids (orchidaceae)
Subfamily : Orchidoideae
Tribe : Cranichideae
Sub tribus : Pterostylidinae
Genre : Pterostylis
Scientific name of the  sub-tribus
Pterostylidinae
Pfitzer
Scientific name of the  genus
Pterostylis
R.Br.

Pterostylis is a plant genus in the family of orchids (Orchidaceae). The approximately 270 species occur mainly in Australia , but also on New Zealand , New Caledonia , Papua New Guinea and other islands in the vicinity. They are small, perennial , herbaceous plants that, as geophytes, survive the unfavorable season with a tuber. The leaves can be different in flowering and non-flowering specimens of the same species. The flowers are predominantly green in color, and their scent attracts male flies. Noteworthy is the central petal, the lip , which moves in contact, including the pollinating insect and forces along the dust sheet and the scar to escape from the flower. Some species are used as ornamental plants . The genus Pterostylis forms its own subtribe Pterostylidinae.

description

Illustration by Pterostylis curta from Curtis's Botanical Magazine , Volume 58 (NS 5), 1831, plate 3086
In rosettes arranged leaves of Pterostylis curta
Foliage leaves of Pterostylis melagramma distributed along the stem axis

Appearance

The Pterostylis species are perennial , herbaceous plants . These geophytes form an underground tuber with which they survive the unfavorable season. Most species grow terrestrially so they usually have roots in the ground, some species can also grow epiphytically .

Roots, tubers and runners

The subterranean tubers consist - typical of the subfamily Orchidoideae - mainly of root tissue that surrounds a piece of stem axis from which the plant sprouts again. The tubers are fleshy and usually rounded in shape. Some species related to Pterostylis biseta have clearly flattened tubers, some species around Pterostylis spathulata elliptical to teardrop-shaped. The tubers have a lifespan of 10 to 12 months and are then replaced with new ones. Depending on the species, only one new tuber or several will be formed. The new tuber sits at the end of a thick, runners-like root. In species that form several new tubers, these runners are usually quite long and grow horizontally. This enables vegetative reproduction , and over time, colonies of plants can form. Species with only one new tuber usually form them close to the old one on a short, often vertically growing runners. Various crystals are found in the tubers: raphids in the cortex , often in idioblasts under the epidermis , rarely also in the marrow; rod-shaped crystals in some species in the cortex.

The tubers are surrounded by a velamen radicum , a layer consisting of one to three layers of dead cells. The outer cell walls of the uppermost layer are thickened and corked , and unicellular hairs occasionally arise from the outermost cell layer. In the exodermis below the velamen, corked cell walls can also occur in some species. The tuber is usually traversed by a single, undivided, 8 to 40-rayed stele . The foothills are also surrounded by velamen, here there are multicellular hairs. These hairs and the outer cell layers of the runners are involved in the typical mycorrhiza of orchids. In some species there are raphids under the epidermis.

The roots are thin and fibrous. Multicellular hairs and mycorrhizal fungi are also found here. Raphids are present in the cortex of the roots in most species, and in some also in the epidermis.

Shoot axis and leaves

A single stem axis arises from the tuber. The subterranean part is covered with multicellular hair, here too mycorrhizal fungi can be found in the outer cell layers. Raphids or rod-shaped crystals can usually be found in the cortex.

The leaves are either crowded in a rosette or are spaced along the stem axis. The foliage leaves arranged in rosettes can, depending on the species, lie horizontally on the ground or rather stand upright, sometimes the leaf rosette is also arranged a few centimeters above the substrate. Rosette leaves can be stalked or sessile, while leaves that are distributed along the stem axis have no petioles. The uppermost leaves are smaller than the lower ones, further up on the stem there may also be leaves that are reduced to bracts and lie against the stem axis. The leaf margin is entire or wavy, in species from dry regions there are often transparent, silicate-containing cells on the leaf margin. The nerve consists of a clearly protruding central rib, the lateral veins run towards the tip of the leaf parallel to the leaf margin (acrodroma) and can converge at their ends. Reticulated veining does not occur. The leaves are bare. Depending on the species, stomata occur only on the underside of the leaf or on both sides of the leaf. The cuticle is thin, the epidermis of the leaves often contains branched crystals, rod-shaped crystals or raphids. The palisade parenchyma consists of only one or two layers of cells and can be completely absent. The sponge parenchyma is three to eight cell layers thick, and also thicker on the midrib. Crystals are also often found in the mesophyll .

In some species around Pterostylis rufa and Pterostylis mutica , the leaves of the leaf rosette bend downwards after a short time when the plants are removed from the ground. The plant is likely to press the leaves to the ground to collect dew and rain under the leaves or to reduce water loss from the underside of the leaves.

The arrangement of the tuber, rosette of leaves, leafy shoot and inflorescence is different depending on the species. If a plant does not flower in a year - for example because it is still young or the environmental conditions are unfavorable - it forms a rosette of leaves from the tuber. In the basic pattern of flowering plants, the sprout arises from the tuber, forms a leaf rosette, and the stem axis continues above the leaf rosette as an inflorescence stalk. In some species, flowering and non-flowering plants show different growth patterns: If a plant does not flower in a year, it forms a rosette of leaves, while flowering plants have leaves that are spaced apart on the stem axis. As a further variation, there are species in which flowering plants form a shoot with very reduced leaves and the inflorescence, a leaf rosette grows to the side of a branch of the shoot.

Illustration of Pterostylis banksii
Flower of Pterostylis coccinea , sepals and lateral petals removed
(1) - lip
(2) - joint of the lip
(3) - column - stigma
(4) - column - stamen

Inflorescences and flowers

The inflorescence is terminal and contains one or more flowers . The flowers are resupinated , they mostly point away from the peduncle , but in the species around Pterostylis parviflora they are oriented inwards towards the peduncle.

The hermaphrodite flowers are zygomorphic and threefold. Of the three outer bracts ( sepals ), the two lateral ones are fused together at their base and form a so-called synsepalum. The front half of these bracts is free and ends long drawn out. These tips are very variable in design: from relatively broad-triangular to thread-shaped, the ends partly still thickened in a club-shaped manner or provided with a longitudinal groove. The tips can point in the same direction as the petal on which they are attached, or they can be curved differently, in Pterostylis recurva they can be bent almost at right angles. In Pterostylis woollsii , the tips of the synsepalum are up to 15 cm long. The synsepalum can point upwards or downwards - a feature according to which the genus can be systematically divided into two groups. Its shape can be flat, but also bulged in the shape of a bowl. The third, upward-pointing sepalum and the two lateral inner bracts ( petals ) adhere to one another and form a hood. The lateral petals are asymmetrically curved in a sickle shape, their edge usually hangs in a groove that runs along the sides of the sepalum.

The third petalum, the lip , is free; In contrast to the other bracts, it does not start at the end of the ovary , but with a narrow base ( nail (botany) ) on the column . The lip is entire or three-lobed, it can have an appendage at the base. The surface of the lip can be smooth, covered with reflective cells, with rounded or pointed cells on the surface, or with different hairs. The lip usually ends with entire margins, but can also be incised or bilobed, in some species the whole tip is thickened or has a spherical thickening. The basal appendage of the lip is shaped very differently in different species, it ranges from thread-like, entire to three-lobed or rounded-cartilaginous. When touched, the lip moves and describes an arc of about 30 to 150 ° around a joint at its base. In species with the synsepalum pointing downwards, the lip is visible, the appendage is only slightly developed, the movement is triggered by touching the lip. If the synsepalum points upwards, the lip is covered by it, the basal appendage of the lip is well developed in these species and triggers the movement of the lip when touched. After the rotation, the lip will remain in the new position for between five and 30 minutes before moving back to the starting position. After another ten minutes or so, the movement can be triggered again.

The curved column has various appendages, which are shaped differently depending on the type: lateral wings, hair or cilia. The wings are bent forward and together with the column form a tube. At the top of the column is a stamen that contains four yellow, linear to club-shaped pollinia with a flour-like consistency. Few studies have been carried out on the pollen grains: a network-like shape of the surface was found. It is stated differently whether the pollen grains are present individually or in tetrads. The scar is lobed. The separating tissue between the stamen and the stamen is well developed and contains an adhesive gland (Viscidium).

Pterostylis stenochila : after fertilization, fruit formation, the bracts remain on the capsule fruit

Fruits and seeds

In some species, the flower stalk elongates until the capsule fruit is ripe . The capsule fruit are elongated-elliptical with three longitudinal ribs. The dried bloom cladding leaves stick to the capsule fruit. The capsule fruit opens with three slits and releases the seeds.

The seeds are elliptical, the paper-like integument is widened like a wing and surrounds the embryo . The seeds can be assigned to the so-called Goodyera type, in which the cells of the integument are all about the same size and are roughly square or somewhat elongated. There are noticeable gaps between the cells.

Protocorm

During germination , a protocorm that depends on mycorrhizal fungi is initially formed . There are two types within the genus: in most species the protocorm is obovate, thicker towards the top and grows towards the top. In species around Pterostylis rufa , Pterostylis barbata and Pterostylis recurva , the protocorm initially grows downwards (positive geotropic) and only later bends upwards.

Karyology

Chromosome counts are only available for a few species . For most of the species examined, it is 2n = 50, but 2n = 42, 2n = 52 and 2n = 54 have also been detected.

Life cycle

The seeds of Pterostylis ripen about three to six weeks after the flowers are pollinated . Germination takes place immediately in good conditions, but the seeds can also survive the dry summer months. In order to germinate, the seed has to hit a mycorrhizal fungus that reaches the embryo through the micropyle , fungal threads grow into the embryo and are digested there by the orchid. The Protokorm grows depending on the fungus. In good conditions, plants will bloom for the first time two or three years after germination.

Pterostylis occurs in areas with a seasonal climate, the plants survive the hot, dry season with their tubers and grow during the rainy season. Usually the dry season in the area of ​​the genus does not last longer than two or three months. For species from the southernmost area as well as species from the high altitude of the mountains, the rest period is dictated by the cold. During the dormant period there are hardly any mycorrhizal fungi in the tuber, when the growth begins, the mycorrhiza forms anew on the new roots and on the underground part of the stem axis.

Many species grow in ecosystems that are characterized by frequent fires. In contrast to other Australian orchids, the plants do not bloom better after a fire, but the bloom is weaker in such years.

ecology

pollination

Most Pterostylis species are pollinated by insects ( entomophilia ), some species also self-pollinate . The flowers offer no nectar or other benefits for the pollinators, they are deception flowers , at least some of the species are sex deception flowers . Small flies from the families Mycetophilidae and Culicidae were observed as pollinators . Although hardly any Pterostylis species exudes a floral scent that can be perceived by humans (the exception are species around Pterostylis parviflora , which clearly smell of sperm, especially in damp or humid weather), the pollinators fly towards the flowers against the wind and probably follow one Scent. The activity of the flies on the flowers is greatest in thunderstorm weather or when the air pressure drops significantly.

The pollination mechanism differs depending on whether the synsepalum faces up and covers the lip, or if it faces down and the lip is visible. In the first case, the insect lands on the outside of the flower and crawls inwards, reaches the lip there and continues on the lip towards the inside of the flower. At some point the insect triggers the movement of the lip - the lip moves around its joint, pressing the insect against the column. The way out of the flower is now largely blocked for the insect. Different parts of the flower, such as the lip, the column, the wings of the column, including their hair, interlock and leave no gap for the little flies. Probably alarmed by the movement of the lip and the blocked path, the insects try to leave the flower quickly. The only way is along the column, past the scar, the glue gland and then the stamen. First, any pollen grains hanging on the insect are placed on the stigma, then the insect is coated with sticky liquid and finally pollen is attached to the stamen. This sequence prevents your own pollen from landing on the stigma of the flower. The Pterostylis species with a visible lip are pollinated only by male flies. When approaching the lip, they extend their genitals and land directly on this petal. In some plants, the lip is shaped similar to that of the female insect. The movement of the lip is triggered directly by the landing of the fly, the insect is pressed against the column and has to leave the flower along the path described above.

The species in which self-pollination occurs, the pollinia are crumbly and fall by themselves onto the scar below.

Seed spread

The seeds of all species are spread by the wind ( anemochory ). Although the seeds are very light, the majority land a relatively short distance away. In some species, the flower stalk elongates between pollination and seed maturity (species around Pterostylis parviflora , Pterostylis mutica ). In the two species Pterostylis uliginosa and Pterostylis humilis , the entire peduncle thickens and elongates during this time, which allows the seeds to spread further.

Mycorrhiza

All species rely on mycorrhizal fungi for germination. These fungi can also be found in fully grown plants, especially on the subterranean part of the shoot. The roots of the Pterostylis species are very sparsely developed, which indicates that the plants are largely dependent on the mycorrhizal fungi for their nutrition. The fungi involved belong to the genus Ceratobasidium within the Tulasnellales . An exact determination of the fungus species is difficult, based on DNA examinations different lineages can be differentiated, many of which are closely related to Ceratobasidium cornigerum . Some groups within the genus Pterostylis can be assigned to a certain type of fungus, i.e. closely related plant species harbor the same fungus. This applies to the sections Catochilus and Stamnorchis , the species of which have almost identical mycorrhizal fungi, even if they grow geographically far apart. Species from the Hymenochilus and Oligochaetochilus sections show the same specialization in a common fungus that can be distinguished from other Pterostylis sections. The sections Catochilus and Stamnorchis are closely related, as are the sections Hymenochilus and Oligochaetochilus , so here the dependence on a special mushroom species reflects the relationship. Closely related mushrooms are found in closely related orchid species, and vice versa, a mushroom species is only found in orchids that are closely related. This does not apply to the entire genus Pterostylis : there are also counterexamples where the relationships between the mycorrhizal partners do not have anything in common. The species in the Pterostylis section have a number of different fungal partners; the other way around , the same fungi are found in species from the Pharochilum , Urochilos and Parviflorae sections that are not particularly closely related .

When the seeds germinate, an assignment of certain types of fungus and Pterostylis species can also be determined in the laboratory . The seeds generally germinate better if the mycorrhizal fungus comes from the same or a closely related Pterostylis species. The dependency on a certain type of fungus during germination and as adult plants correlates with each other: the types of the section Pterostylis in which different fungi have been isolated from adult plants can also germinate quite well with different fungi. In sections that, as an adult plant, depend on very specific fungi, the seeds also show a significantly better germination rate with this same type of fungus.

Occurrence

The Pterostylis species occur mainly in Australia, furthermore in New Zealand, New Guinea, New Caledonia , New Britain , New Ireland and on Seram . The southernmost point of the area is Stewart Island south of New Zealand, the northernmost point in New Guinea is almost at the level of the equator. Altitudes from sea level to 3600 meters are settled in New Guinea. The majority of the species and the greatest diversity can be found in southern Australia. About 30 species are native to New Zealand, five to New Caledonia and only four to Melanesia .

The Pterostylis species colonize very different locations, especially in the temperate climate . Grasslands, bushes, open forests and even rainforests are populated. The soils can consist of acid sands, limestone or granite, some species are also found in bogs and swamps as well as on river banks. The dry interior of Australia, however, is not reached by Pterostylis . The ecological amplitude of the species is very different: some species are widespread, Pterostylis aspera , Pterostylis curta and Pterostylis nutans, for example, can also be found in planted pine plantations. However, many species have specialized in special locations, for example Pterostylis tenuissima only grows in calcareous swamps near the coast.

Systematics and botanical history

The genus Pterostylis left its first traces in scientific literature in an illustrated work on Joseph Banks ' journey. There you can see a combination of three flowers, probably from Pterostylis revoluta and leaves from Pterostylis acuminata . In an unpublished manuscript Daniel Solander assigned the scientific name Arethusa tetrapetala for the species known today as Pterostylis revoluta . Early herbarium specimens can be found in the J. E. Smith Herbarium of the Linnean Society of London . They were collected by John White between 1788 and 1794 and by Jacques Labillardière in 1792 . In 1806 Labillardière described a species under the name Disperis alata .

Excerpt from the first description

George Caley and Robert Brown were the first collectors to collect a large number of species and specimens in their herbaria . Both were active in the southeast of Australia between 1800 and 1810, perhaps they collected together, in any case, Brown's herbarium contains some plants that Caley collected. Robert Brown described the genus with 19 species in his work " Prodromus floræ Novæ Hollandiæ " in 1810 . The type species is Pterostylis curta . The generic name Pterostylis is made up of the Greek components πτερόν pteron for wing or feather, and στῦλος stylos for column or stylus ; it refers to the clear wings on the side of the stamen on the column .

External system

There were various early classifications of the genus Pterostylis within the orchid family: Lindley placed them in the Arethuseae tribe in 1840 , and Endlicher followed him in this view in 1842. George Bentham saw the genus in the tribe Neottieae in 1873 , later he placed it in the work Species plantarum, published together with Hooker in 1883, in the tribe Diurideae . Pfitzer set up a subtribe Pterostylidinae in 1887, in which he gathered the genera Pterostylis , Caleana and Drakaea . Schlechter doubted the close relationship of these three genera and established the Subtribus Drakaeinae in 1926 , so that Pterostylis remained as the only genus of the Subtribus Pterostylidinae within the Diurideae. This classification remained largely stable for the next 70 years. Also Dressler followed her, but noted that Pterostylis be clearly distinguished from the other Diurideae and the next of kin were unclear within the tribe.

From 1995, first studies of embryonic development, of seeds and then of DNA studies led to a completely different view. Accordingly, Pterostylis is not closely related to the tribe Diurideae, but belongs to the tribe Cranichideae . The findings on the subtribe Chloraeinae and Achlydosa were very similar - initially counted among the Diurideae, the more recent studies placed them among the Cranichideae. The exact relationships of the basal groups of the tribe Cranichideae are still quite unclear, a cladogram from a study by Salazar , Chase , Soto Arenas and Ingrouille looks like this:






Pterostylis


   

Achlydosa



   

Pachyplectron (Goodyerinae)


   

remaining Goodyerinae




   


Spiranthinae


   

Cranichidinae


   

Manniella


Template: Klade / Maintenance / 3

   

Galeottiella




   

Chloraeinae



   

Diurideae


Template: Klade / Maintenance / Style

Internal system

Pterostylis alpina , clearly visible the upward-pointing synsepalum and the hidden lip - a representative of the subgenus Pterostylis
Pterostylis melagramma , the synsepalum points downwards and does not cover the lip - a representative of the subgenus Oligochaetochilus

When the genus was first described, Brown classified the species known to him into four groups. The first three of Brown's informal groups were formally described by Don in 1830 as sections . Lindley in 1840, Reichenbach in 1871, Bentham in 1873, Pfitzer in 1889 and Rupp in 1933 made further, sometimes quite different internal classifications of the genre . The numerous newly described species by other authors have only rarely been included in one of these classifications. In horticultural circles, separate names have become commonplace for individual easily delimited groups.

In 2001 and 2002 two edits on the systematics of the genus Pterostylis were published in quick succession . In his review article Genera et Species Orchidalium , Szlachetko divided the genus into three parts: Pterostylis and the two newly described Oligochaetochilus and Plumatichilos . The monograph by Jones and Clements had to take into account the work of Szlachetko, since names that were given earlier take precedence. However, the two Australian researchers did not adopt Szlachetko's concept, but presented a subdivision of Pterostylis into 16 individual genera.

As a result, the splitting of Australian orchid taxa in particular was criticized as a “taxonomic turmoil down-under”. Although Jones and Clements had used cladistic methods and DNA studies, further work challenged the monophyly of some of the new genera. A number of Australian institutions, such as those involved in the Australian Plant Census and the Australian Plant Names Index, as well as most herbaria , decided to keep the genus Pterostylis in its "classic" form and not to follow the work of Jones and Clements. As an alternative, Janes and Duretto presented a structure that Pterostylis does not subdivide into several genera, but rather provides internal ranks such as subgenus and section .

If you take the genus Pterostylis according to Janes and Duretto 2010 in a broader sense, then synonyms for Pterostylis R.Br. nom. cons .: Diplodium Sw. , Oligochaetochilus Szlach. , Plumatichilos Szlach. , Bunochilus D.L. Jones & MAClem. , Crangonorchis D.L. Jones & MAClem. , Eremorchis D.L. Jones & MAClem. , Hymenochilus D.L. Jones & MAClem. , Linguella D.L. Jones & MAClem. , Petrorchis D.L. Jones & MAClem. , Pharochilum D.L. Jones & MAClem. , Ranorchis D.L. Jones & MAClem. , Speculantha D.L.Jones & MAClem. , Stamnorchis D.L. Jones & MAClem. , Taurantha D.L. Jones & MAClem. , Urochilus D.L. Jones & MAClem. , × Taurodium D.L. Jones & MAClem.

Illustration of Pterostylis acuminata from Curtis's Botanical Magazine , Volume 62
Pterostylis banksii
Pterostylis barbata
Illustration by Pterostylis baptistii from Curtis's Botanical Magazine , Volume 104 (Series 3, No. 34), 1878, Plate 6351
Illustration by Pterostylis concinna from Curtis's Botanical Magazine , Volume 62
Illustration by Pterostylis nutans from Curtis's Botanical Magazine , Volume 52
Pterostylis nutans
Pterostylis plumosa
Pterostylis recurva
Pterostylis revoluta
Pterostylis sanguinea
Pterostylis sargentii
Pterostylis stenochila
Pterostylis trullifolia
Pterostylis umbrina
Pterostylis × furcillata

The genus Pterostylis is therefore divided into two sub-genera, each containing about half of the species. The subgenus Pterostylis is further divided into three sections , the subgenus Oligochaetochilus into seven sections:

Subgenus Pterostylis :
Characterized by upwardly directed lateral sepals (obliquely upward in Pterostylis porrecta ), the lip is unlapped, without cilia, the basal appendage is brush-shaped. The inflorescence is single-flowered or, if multi-flowered, with short peduncles and flowers that point towards the peduncle. Some species form colonies through vegetative reproduction.
Section Pterostylis :
Flowering and non-flowering plants have the same vegetative characteristics, the leaves are in a basal rosette or are loosely arranged in a spiral. The leaves on the peduncle are reduced to small bracts. Vegetative reproduction occurs in all species. The flowers appear individually, the lateral sepals are directed upwards or diagonally upwards, they end long and thin, a clear gap can be seen between the lateral sepals and the upper sepal.
The section Pterostylis contains about 50 species with a wide distribution area, but it is absent in western Australia. This section is the basal clade in the subgenus Pterostylis , that is, it is the sister taxon of the other two sections. This section contains the type species of the genus with Pterostylis curta , therefore it bears the same name as the genus.
Section Foliosae G.Don :
Flowering and non-flowering plants are vegetatively developed the same or different depending on the species. In non-flowering plants, the leaves are in a basal rosette or loosely spiral, in flowering plants the leaves can be in a rosette or distributed along the stem axis. All species also reproduce vegetatively. The flowers appear individually, the lateral sepals are directed upwards, they end like a thread, there is no gap between the lateral sepals and the upper sepal.
The Foliosae section also contains about 50 species, the range includes Australia and New Zealand. This section is the sister taxon of the Parviflorae section . The type species of the section is Pterostylis grandiflora . Clements and Jones subdivide this section into the genera Crangonorchis , Diplodium , Eremorchis , Linguella and Taurantha .
Section Parviflorae (Benth.) Janes & Duretto :
Flowering and non-flowering plants differ in their vegetative characteristics: in non-flowering plants the leaves are in a basal rosette, in flowering plants one or more lateral leaf rosettes are formed. There are leaves or reduced bracts on the peduncle. Vegetative reproduction does not occur. The inflorescence is multi-flowered, the pedicels are short, the flowers point towards the peduncle. The lateral sepals are directed upwards, they end relatively short and obtuse triangular.
The Parviflorae section contains eleven species with a distribution area in southeastern Australia. Type species of the section is Pterostylis parviflora . Clements and Jones divide this section into the genres Petrorchis and Speculantha .
Subgenus Oligochaetochilus :
In this sub-genus, the lateral sepals point downwards, rarely diagonally downwards or first upwards with the tips then bent downwards. The lip can be lobed, cilia can be present, the basal appendage can be brush-shaped, ribbon-shaped, three-lobed or completely absent. The inflorescence is single or multi-flowered, the flowers point outwards. Vegetative reproduction does not occur.
Section Hymenochilus (DLJones & MAClem.) Janes & Duretto :
Flowering and non-flowering plants have the same vegetative characteristics, the leaves are in a basal rosette. The leaves on the peduncle are reduced to small bracts. The inflorescence is multi-flowered, the flowers point outwards. The lateral sepals point downwards, they end briefly triangular. The lip is undivided, ciliate very briefly, the basal appendage is ribbon or beak-shaped.
The Hymenochilus section contains 16 species, the range extends over southern and eastern Australia and New Zealand. It is the sister taxon to a clade from the other six sections of the subgenus Oligochaetochilus . The type of dissection is Pterostylis muticus .
Section of Catochilus Benth. :
In this section, flowering and non-flowering plants are alike, the leaves are in a basal rosette as well as in a spiral on the stem axis, decreasing upwards to reduced bracts. The inflorescence is single-flowered. The lateral sepals point downwards, they end in a long linear manner. The lip is undivided, with long, yellow hair, the basal appendage is beak-shaped.
Four species make up this section, the sister taxon of which has not been clarified within the subgenus. The distribution area includes southern Australia and New Zealand. Type species is Pterostylis barbata . Szlachetko as well as Clements and Jones see this section in the genus rank under the name Plumatichilos .
Section Oligochaetochilus (Szlach.) Janes & Duretto :
Flowering and non-flowering plants have the same vegetative characteristics, the leaves are in a basal rosette. The leaves on the peduncle are reduced to small bracts. The inflorescence is multi-flowered, the flowers point outwards. The lateral sepals point downwards, they end in a long, thread-like manner. The lip is undivided, covered with conspicuous white hairs, a basal appendage is missing.
With 47 species the largest section of the subgenus, as with the previous section, the sister taxon is not clear. Distribution area is Australia. Type species of the section is Pterostylis rufa .
Section Stamnorchis (DLJones & MAClem.) Janes & Duretto :
Flowering and non-flowering plants are vegetatively developed differently. In non-flowering plants the leaves are in a basal rosette, in flowering plants only distributed along the stem axis. The inflorescence is multi-flowered, the flowers point outwards. The two lateral sepals, as far as they have grown together, point diagonally upwards, the free tips are bent downwards, they end in a long, thread-like manner. The lip is three-lobed, without noticeable hair, with a brush-shaped basal appendage.
The section is monotypical with the only species Pterostylis recurva from southwest Australia. The sister taxon is unclear.
Pharochilum Section (DLJones & MAClem.) Janes & Duretto :
Flowering and non-flowering plants are vegetatively different, in non-flowering plants the leaves are in a basal rosette, in flowering plants one or two leaf rosettes are formed on the side, while only reduced bracts are on the flowering stem. The inflorescence is multi-flowered, the flowers point outwards. The two lateral sepals point diagonally downwards, they end in a long thread-like manner. The lip is three-lobed with large lateral lobes, without hair and without a basal appendage.
Monotypical section with Pterostylis daintreana as the only species, it has an area in eastern Australia. The sister taxon is unclear.
Section Urochilus (DLJones & MAClem.) Janes & Duretto :
Flowering and non-flowering plants differ vegetatively: non-flowering specimens form a basal rosette of leaves, in flowering plants the leaves are distributed on the stem. The inflorescence is multi-flowered, the flowers point outwards. The lateral sepals point downwards, they end long, thread-like drawn out or short triangular. The lip has at most very small hairs, it is three-lobed with a three-part basal appendage.
This section includes four species from southern Australia. Sister taxon is the Squamatae section . The type species is Pterostylis vittata . Clements and Jones subdivide this section into the genera Ranorchis and Urochilus .
Section Squamatae G.Don :
The species of the Squamatae section resemble those of the Urochilus section . The distinguishing feature is the basal appendage of the lip, which is absent in Squamatae . The 27 species all come from southeastern Australia. Type species is Pterostylis longifolia . Clements and Jones see this genus section under the name of Bunorchis .

List of species and hybrids

A list of the recognized species of the genus Pterostylis with their distribution can be found in R. Govaerts:

Nothospecies:

See also

literature

  • Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (Eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae . tape 3/2 . Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 , pp. 156-164 .
  • David L. Jones, Mark A. Clements: A Review of Pterostylis (Orchidaceae) (=  Australian Orchid Research . Volume 4 ). Australian Orchid Foundation, 2002, ISBN 0-642-54904-4 .

Individual evidence

  1. ↑ a b c d e f g h i j k l Rafaël Govaerts (Ed.): Pterostylis. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved March 28, 2020.
  2. ^ A b c d Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, Cambridge 1993, ISBN 0-521-45058-6 , pp. 133 .
  3. ↑ a b c d e f g h i j k l m n o p q r s t u v w David L. Jones, Mark A. Clements: A Review of Pterostylis (Orchidaceae). Australian Orchid Foundation, 2002, ISBN 0-642-54904-4 .
  4. ↑ a b c d e f g h i Alec M. Pridgeon, Phillip Cribb, Mark W. Chase, Finn Rasmussen (eds.): Genera Orchidacearum. Orchidoideae (Part 2). Vanilloideae. 3/2, Oxford University Press, New York and Oxford 2003, ISBN 0-19-850711-9 , pp. 156-164.
  5. ^ Robert L. Dressler: Phylogeny and Classification of the Orchid Family . Cambridge University Press, Cambridge 1993, ISBN 0-521-45058-6 , pp. 52 .
  6. ↑ a b J. Tupac Otero, Peter H. Thrall, Mark Clements, Jeremy J. Burdon, Joseph T. Miller: Codiversification of orchids (Pterostylidinae) and their associated mycorrhizal fungi . In: Australian Journal of Botany . tape 59 , 2011, p. 480-497 , doi : 10.1071 / BT11053 .
  7. ↑ Hubert Mayr: Orchid names and their meaning . Berger, 1996.
  8. ↑ Gerardo A. Salazar, Mark W. Chase, Miguel A. Soto Arenas, Martin Ingrouille: Phylogenetics of Cranichideae with emphasis on Spiranthinae (Orchidaceae, Orchidoideae): evidence from plastid and nuclear DNA sequences . In: American Journal of Botany . tape 90 , no. 5 , 2003, p. 782 .
  9. ^ Dariusz L. Szlachetko: Genera et Species Orchidalium. I . In: Polish Journal of Botany . tape 46 , no. 1 , 2001, p. 11-26 .
  10. ↑ Stephen D. Hopper: Taxonomic tower down-under: recent developments in Australian orchid systematics . In: Annals of Botany . tape 104 , 2009, p. 447-455 , doi : 10.1093 / aob / mcp090 .
  11. ↑ Jasmine K. Janes, Dorothy A. Steane, René E. Vaillancourt, Marco F. Duretto: A molecular phylogeny of the subtribe Pterostylidinae (Orchidaceae): resolving the taxonomic confusion . In: Annals of Botany . tape 23 , 2010, p. 248-259 , doi : 10.1071 / SB10006 .
  12. ↑ a b c Jasmine K. Janes, Marco F. Duretto: A new classification for subtribe Pterostylidinae (Orchidaceae), reaffirming Pterostylis in the broad sense . In: Australian Systematic Botany . tape 23 , 2010, p. 260-269 , doi : 10.1071 / SB09052 .

Web links

Commons : Pterostylis  - album with pictures, videos and audio files