''Corsia'' is a little-studied plant

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

from the

monocotyledon Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Corsiaceae Corsiaceae is a family of monocotyledonous flowering plants. The APG II system (2003) treats the family in the order Liliales, in the clade monocots. This is a slight change from the APG system, of 1998, which left the family unplaced as to order ...

. 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, particularly New Guinea, and Australia. He has been called the greatest botanist to ever study Malesia. His author abbreviat ...

and contains 25 species, all of which lack

chlorophyll Chlorophyll (also chlorophyl) 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 allow plants to a ...

and

parasitize Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

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

for nutrition. All 25 species are distributed through

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

, 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 50,000 square km. History The first inhabitants o ...

, the

Solomon Islands Solomon Islands is an island country consisting of six major islands and over 900 smaller islands in Oceania, to the east of Papua New Guinea and north-west of Vanuatu. It has a land area of , and a population of approx. 700,000. Its capita ...

and

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

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 Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respective ...

(''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 shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

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 in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...

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. Abzug_Infloreszenz_Ausschnitt_Blüte

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 spirall ...

, 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 sign ...

''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. Along with the Asteraceae, they are one of the two largest families of flowering ...

, 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 which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

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, dew, or fog to be present. Humidity depe ...

among decaying leaves. The

center of diversity A center of origin is a geographical area where a group of organisms, either domesticated or wild, first developed its distinctive properties. They are also considered centers of diversity. Centers of origin were first identified in 1924 by Ni ...

for the genus is

. All 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 elsew ...

to New Guinea (including the

), the

, and

Ecology

Like other members of

, ''Corsia'' species lack

and are thus incapable of

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

. Instead, they are

myco-heterotrophs Myco-heterotrophy (from Greek μύκης , "fungus", ἕτερος ', "another", "different" and τροφή ', "nutrition") is a symbiotic relationship between certain kinds of plants and fungi, in which the plant gets all or part of its food fr ...

, relying exclusively on

parasitizing Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

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

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 (f ...

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 or ...

of saprotrophic fungi with enzymes and absorb the resulting nutrients. The

host species In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include a ...

of ''Corsia'', and whether ''Corsia'' are even

host specific In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include a ...

, 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

of the order

Liliales Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) place ...

. 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. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

and '' Arachnitis'' of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. 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, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

naturalist

from specimens from

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

Burmanniaceae Burmanniaceae is a Family (biology), 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 m ...

by the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

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 studi ...

in 1883 and grouped together with orchids (family

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 ...

). 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 cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

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 (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

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 of flowering plants. The family consists of two genera and four species of perennial herbaceous plants endemic to New Caledonia and Tasmania. Taxonomy Originally described by Dumortier in 1829, Campy ...

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

Thismia ''Thismia'' is a genus of myco-heterotrophic plants in family Burmanniaceae, first described as a genus in 1845. It is native to East and Southeast Asia, New Guinea, Australia, New Zealand, and the Americas. ; Species * '' Thismia abei'' Hatu ...

'' and/or ''Burmannia'' of

Dioscoreales The Dioscoreales are an order of monocotyledonous flowering plants in modern classification systems, such as the Angiosperm Phylogeny Group and the Angiosperm Phylogeny Web. Within the monocots Dioscoreales are grouped in the lilioid monocots ...

.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 Japan, Jobi) is an island of 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 Mios Num Island a ...

Island) *''

Corsia unguiculata ''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. (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 ''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 nutrition ...

'' Gibbs (Western New Guinea, including Yapen Island) *'' Corsia boridiensis'' P.Royen (Papua New Guinea) *'' Corsia brassii'' P.Royen (Papua New Guinea) *'' Corsia clypeata'' P.Royen (Papua New Guinea) *'' Corsia cordata'' Schltr. (Papua New Guinea) *''

Corsia crenata ''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 nutrition ...

'' J.J.Sm. (Indonesia) *''

Corsia cyclopensis ''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 nutrition ...

''P.Royen (Papua New Guinea and Indonesia) *''

Corsia dispar ''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 nutrition ...

'' D.L.Jones & B.Gray (Herberton Range in Queensland, Australia) *''

Corsia haianjensis ''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 nutrition ...

'' P.Royen (Papua New Guinea and Solomon Islands) *''

Corsia huonensis ''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 nutrition ...

'' P.Royen (Papua New Guinea) *''

Corsia lamellata ''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 nutrition ...

'' Schltr. (Papua New Guinea) *''

Corsia merimantaensis ''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 nutrition ...

'' P.Royen (New Guinea) *'' Corsia ornata'' Becc. (Papua New Guinea) *''

Corsia papuana ''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 ...

'' P.Royen (Papua New Guinea) *'' Corsia pyramidata'' P.Royen (Papua New Guinea and Solomon Islands) *'' Corsia resiensis'' P.Royen (Western New Guinea) *'' Corsia torricellensis'' 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