''Corsia'' is a little-studied plant

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 ...

from the

monocotyledon Monocotyledons (), commonly referred to as monocots, ( Lilianae '' sensu'' Chase & Reveal) are flowering plants whose seeds contain only one embryonic leaf, or cotyledon. A monocot taxon has been in use for several decades, but with various ranks ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Corsiaceae. It was first described in 1877 by Italian naturalist

Odoardo Beccari Odoardo Beccari (16 November 1843 – 25 October 1920) was an Italian botanist famous for his discoveries in Indonesia, New Guinea, and Australia. He has been called the greatest botanist to ever study Malesia. Life Youth and education (18 ...

and contains 25 species, all of which lack

chlorophyll Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words (, "pale green") and (, "leaf"). Chlorophyll allows plants to absorb energy ...

and parasitize

fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

for nutrition. All 25 species are distributed through

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

, the

Bismarck Archipelago The Bismarck Archipelago (, ) is a group of islands off the northeastern coast of New Guinea in the western Pacific Ocean and is part of the Islands Region of Papua New Guinea. Its area is about . History The first inhabitants of the archipela ...

, the

Solomon Islands Solomon Islands, also known simply as the Solomons,John Prados, ''Islands of Destiny'', Dutton Caliber, 2012, p,20 and passim is an island country consisting of six major islands and over 1000 smaller islands in Melanesia, part of Oceania, t ...

and

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 ...

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 ...

Description

In terms of appearance, the species of ''Corsia'' are quite uniform except for the flowers.Paul Kores, David A. White, Leonard B. Thien: ''Chromosomes of Corsia (Corsiaceae)'', American Journal of Botany, Vol. 65, No. 5 (May - Jun., 1978), Page. 584-585, Chromosome counts are known only from two species: ''Corsia cornuta'' and ''C. clypeata''. Both have a diploid number (''2n'') of 18.

Habit

''Corsia'' exist largely underground; only the seldom-formed flower stems develop above ground. The fine, thread-like and hairless root system is weakly branched and whitish, spreading widely just beneath the surface. Several hairless, unbranched and upright flowering stems sprout from a

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

and are visible above ground. They are usually reddish in color and are high. The

xylem Xylem is one of the two types of transport tissue (biology), tissue in vascular plants, the other being phloem; both of these are part of the vascular bundle. The basic function of the xylem is to transport water upward from the roots to parts o ...

is woody and not perforated.

Leaves

The foliage along the stem is evenly distributed, and consists of three to seven broadly ovate pointed leaves. Those on the rhizomes are less developed than the reddish leaves on the flowering stems. Along the stem the leaves grow alternately, at their bases they sheath the stem almost entirely.

Flowers

The growth of ''Corsia'' flowers appears to be triggered by combination of rain and drought, usually by a prolonged rainy season followed by several dry days. The

zygomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spir ...

, trimerous, nodding flowers grow singly and are terminal on the stems. The

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s are colored pale red to brownish red, sometimes with a bit of pale yellow and rarely brownish-green. The six tepals are approximately of the same shape and size, with the exception of the uppermost tepal, termed the labellum, which is considerably larger and usually heart-shaped. The tepals of the species of

section Section, Sectioning, or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sig ...

''Sessilis'' are long and wide. The tepals of the section ''Unguiculatis'' are long and wide. The labellum is about long and wide. The labellum encloses the floral bud until its opening, thereby protecting immature floral parts. The labellum is usually simple, but is occasionally bifurcated at the tip of the midrib. The labellum of ''Corsia'' is similar in appearance to the labellum of some

orchids 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. Orchids are cosmopolitan plants that are found in almost every habitat on Earth ...

, but is not homologous to them; in orchids the labellum is formed from an inner tepal (petal), but in Corsiaceae it forms from an outer tepal (sepal). In ''Corsia'', unlike the orchids, all six stamens are fertile.

Fruit and seeds

After pollination (possibly by flies), the peduncles extend and a long and slender cylindrical yellowish brown capsule fruit forms. The small dust-like seeds are about long, thick and colored pale to dark brown. The seed coat tightly encloses the endosperm and its surface is finely grooved longitudinally.J.H. Kirkbride, Jr., C.R. Gunn, and M.J. Dallwitz: ''Family Guide for Fruits and Seeds'', Vers. 1.0, 2006, Retrieved 26 March 2007
Online version
Although the native habitat of ''Corsia'' is relatively calm,

seed dispersal In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

is presumed to be facilitated by wind (

anemochory In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

).C. Neinhuis, P. Ibisch: ''Corsiaceae'', in: K. Kubitzki (Hrsg.): ''The Families and Genera of Vascular Plants, Vol. 3, Lilianae'', p. 200, 1998,

Distribution and habitat

Species of ''Corsia'' are generally found in

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

s and mountain forests at altitudes of above sea level. They grow in

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

-rich soils in shaded areas of high

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

among decaying leaves. The

center of diversity A Vavilov center or center of origin is a geographical area where a group of organisms, either domesticated or wild, first developed its distinctive properties. Centers of origin were first identified in 1924 by Nikolai Vavilov. Vavilov posite ...

for the genus is

. All species are

endemic Endemism is the state of a species being found only 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 foun ...

to New Guinea (including the

), the

, and

Ecology

Like other members of Corsiaceae, ''Corsia'' species lack

and are thus incapable of

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

. Instead, they are myco-heterotrophs, relying exclusively on parasitizing

arbuscular mycorrhiza An arbuscular mycorrhiza (AM) (plural ''mycorrhizae'') is a type of mycorrhiza in which the symbiont fungus (''Arbuscular mycorrhizal fungi'', or AMF) penetrates the cortical cells of the roots of a vascular plant forming arbuscules. Arbuscul ...

for nutrition. Myco-heterotrophs were once mistakenly thought to be

saprotroph Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

ic plants. It is now known that they do not obtain nourishment directly from decaying organic matter, instead they digest the

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

of saprotrophic fungi with enzymes and absorb the resulting nutrients. The host species of ''Corsia'', and whether ''Corsia'' are even host specific, remains unknown. ''Corsia'' are sometimes found growing in association with other myco-heterotrophic plants like '' Burmannia'', ''

Sciaphila ''Sciaphila'' is a genus of mycoheterotrophic plants in the family Triuridaceae. These plants receive nutrition from fungi and neighboring trees and have less need for photosynthesis. It is widespread in tropical and subtropical regions, found i ...

'', and '' Cotylanthera tenuis''.

Taxonomy

''Corsia'' is classified under the family Corsiaceae of the order

Liliales Liliales is an order (biology), order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web List of systems of plant classification, system, within the lilioid monocots. This order of necessity includ ...

. It is one of the three genera currently classified under Corsiaceae, the other two being '' Corsiopsis'' of

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and '' Arachnitis'' of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. It differs from the latter two in having several shoots arising from creeping rhizomes. ''Corsia'' was first described in 1877 by the

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, a Romance ethnic group related to or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance languag ...

naturalist

from specimens from

. He named it after the Marquis Bardo Corsi Salviati. It was classified under

Burmanniaceae Burmanniaceae is a family of flowering plants, consisting of 99 species of herbaceous plants in eight genera. Description These plants are annual or perennial herbs, with generally unbranched stems, some lacking leaves. Some members of this fam ...

by the English botanist

George Bentham George Bentham (22 September 1800 – 10 September 1884) was an English botanist, described by the weed botanist Duane Isely as "the premier systematic botanist of the nineteenth century". Born into a distinguished family, he initially studie ...

in 1883 and grouped together with orchids (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 ...

). In 1938, Fredrik Pieter Jonker separated ''Arachnitis'' and ''Corsia'' from Burmanniaceae based on their strongly

floral characteristics. Kores ''et al.'' (1978) also separated ''Corsia'' from Burmanniaceae after comparing the chromosome numbers of ''C. cornuta'' and ''C. clypeata'' (''2n'' = 18) with the rest of Burmanniaceae (''2n''=32 to 136). Dahlgren & Clifford (1982) tentatively reclassified Corsiaceae as closer to lilies (order

) than to orchids. Cribb ''et al.'' (1995) noted the significant differences between ''Corsia'' and the only other member of Corsiaceae then - ''Arachnitis''. In 1996, Ibisch ''et al.'' challenged the

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of Corsiaceae, positing that ''Arachnitis'' may actually be more closely related to Orchidaceae than ''Corsia'' and recommended the separation of the former into its own family, Arachnitaceae. ''Corsiopsis'' was discovered in 1999 by Zhang ''et al.'' and became the third genus included in the family Corsiaceae. Zhang also remarked that ''Corsiopsis'' seem to be more closely related to ''Corsia'' than to ''Arachnitis''. Based on

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

studies and reexamination of previous morphological studies, Neyland & Hennigan (2003) concluded that ''Corsia'' is not closely related to ''Arachnitis''. The former probably has closer affinities with

Campynemataceae Campynemataceae (Campynemaceae) is a Family (biology), family of flowering plants. The family consists of two genera and four species of perennial herbaceous plants endemism, endemic to New Caledonia and Tasmania. Taxonomy Originally described ...

of Liliales, while the latter may be more closely related to ''

Thismia ''Thismia'' is a genus of myco-heterotrophic plants in family Burmanniaceae, known as "fairy lanterns". They are native to East and Southeast Asia, New Guinea, Australia, New Zealand, and the Americas. Description ''Thismia'' are perennial,' ...

'' and/or ''Burmannia'' of

Dioscoreales The Dioscoreales are an order of monocotyledonous flowering plants, organized under modern classification systems, such as the Angiosperm Phylogeny Group or the Angiosperm Phylogeny Web. Among monocot plants, Dioscoreales are grouped with the ...

.P. F. Stevens (2001 onwards).
Liliales
. ''Angiosperm Phylogeny Website. Version 9, June 2008''. Retrieved 30 December 2011. However, Chase ''et al.'' (2006) concluded that ''Arachnitis'' falls within Liliales while Rudall & Eastman (2002) puts ''Corsia'' closer to either Campynemataceae or ''Thismia''. As such, the taxonomic placement of ''Corsia'' and Corsiaceae remains problematic though they have been tentatively included in Liliales. ''Corsia'' contains two sections, ''Unguiculatis'' and ''Sessilis'', with 25 species. They are listed below along with their distribution ranges: Section ''Unguiculatis'' P.Royen *'' Corsia acuminata'' L.O.Williams (Papua New Guinea) *'' Corsia cornuta'' P.Royen (Papua New Guinea) *'' Corsia purpurata'' L.O.Williams (Papua New Guinea) *'' Corsia triceratops'' P.Royen (

Yapen Yapen (also Japen, Jobi) is an island of Papua (province), Papua, Indonesia. The Yapen Strait separates Yapen and the Biak Islands to the north. It is in Cenderawasih Bay off the north-western coast of the island of New Guinea. To the west is ...

Island) *'' Corsia unguiculata'' Schltr. (Papua New Guinea) *'' Corsia wiakabui'' (W.N.Takeuchi & Pipoly) D.L.Jones & B.Gray (southern New Ireland, Papua New Guinea) Section ''Sessilis'' P.Royen *'' Corsia arfakensis'' Gibbs (Western New Guinea, including Yapen Island) *'' Corsia boridiensis'' P.Royen (Papua New Guinea) *'' Corsia brassii'' P.Royen (Papua New Guinea) *''

Corsia clypeata ''Corsia'' is a little-studied plant genus from the monocotyledon family Corsiaceae. It was first described in 1877 by Italian naturalist Odoardo Beccari and contains 25 species, all of which lack chlorophyll and parasitize fungi for nutriti ...

'' P.Royen (Papua New Guinea) *'' Corsia cordata'' Schltr. (Papua New Guinea) *'' Corsia crenata'' J.J.Sm. (Indonesia) *'' Corsia cyclopensis''P.Royen (Papua New Guinea and Indonesia) *'' Corsia dispar'' D.L.Jones & B.Gray (Herberton Range in Queensland, Australia) *'' Corsia haianjensis'' P.Royen (Papua New Guinea and Solomon Islands) *'' Corsia huonensis'' P.Royen (Papua New Guinea) *'' Corsia lamellata'' Schltr. (Papua New Guinea) *'' Corsia merimantaensis'' P.Royen (New Guinea) *'' Corsia ornata'' Becc. (Papua New Guinea) *'' Corsia papuana'' P.Royen (Papua New Guinea) *'' Corsia pyramidata'' P.Royen (Papua New Guinea and Solomon Islands) *'' Corsia resiensis'' P.Royen (Western New Guinea) *''

Corsia torricellensis ''Corsia'' is a little-studied plant genus from the monocotyledon Family (biology), family Corsiaceae. It was first described in 1877 by Italian naturalist Odoardo Beccari and contains 25 species, all of which lack chlorophyll and Parasitic pl ...

'' Schltr. (Northeast Papua New Guinea) *'' Corsia viridopurpurea'' P.Royen (Papua New Guinea) *'' Corsia wubungu'' P.Royen (Papua New Guinea)

References

Bibliography

* P. Van Royen:''Sertulum Papuanum 17th Corsiaceae of New Guinea and surrounding areas'' in: Webbia 27: pp. 223–255, 1972, * Traudel Rübsamen: '' Morphologische, embryologische und systematische Untersuchungen an Burmanniaceae und Corsiaceae (Mit Ausblick auf die Orchidaceae-Apostasioideae)'' orphological, embryological and systematic studies of Burmanniaceae and Corsiaceae (With view on the Orchidaceae-Apostasioideae) 1986, * Karl Schumann, Karl Lauterbach: ''Nachträge zur Flora der deutschen Schutzgebiete in der Südsee mit Ausschluss Samoa's und der Karolinen'' upplements to Flora of the German protectorates in the Pacific to the exclusion of Samoa's and the Carolinas Leipzig, 1905
Online version
* R. Schlechter: ''Neue Corsiaceae Papuasiens'' ew Papuan Corsiaceae Parisiens in: Botanical yearbooks for systematics, plant geography and plant history, Vol. 49, pp. 109–112, 1913, Stuttgart
Online version
* Dian-Xiang Zhang, Richard M. K. Saunders, Chi-Ming Hu: ''Corsiopsis chinensis gen. et sp. nov. (Corsiaceae): First Record of the Family in Asia'', in: Systematic Botany, Vol. 24, No. 3 (Jul. - Sep., 1999), S. 311-314,
Abstract Online
* {{Taxonbar, from=Q138314 Liliales genera Corsiaceae Parasitic plants Parasites of fungi Taxa named by Odoardo Beccari