Corsia

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, {{ISSN|0002-9122}} Chromosome counts are known only from two species: Corsia cornuta and C. clypeata. Both have a diploid number (2n) of 18.

Corsia exist largely underground;{{cite book | last1=Dahlgren | first1=R. M. T. | last2=Clifford | first2=H. T. | last3=Yeo | first3=P. F. | year=1985 | title=The Families of the Monocotyledons | url=https://archive.org/details/familiesmonocoty00dahl | url-access=limited | location=Berlin | publisher=Springer-Verlag | isbn=978-3-540-13655-2 | pages=[https://archive.org/details/familiesmonocoty00dahl/page/n114 215]–216, 219–220 }} 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 and are visible above ground. They are usually reddish in color and are {{convert|10|to|28|cm|in|abbr=on}} high. The xylem is woody and not perforated.

File:CorsiaSpIILeafEdit.jpg

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.

File:Abzug_Infloreszenz_Ausschnitt_Blüte.jpg

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, trimerous, nodding flowers grow singly and are terminal on the stems. The tepals 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 Sessilis are {{convert|4|to|15|mm|in|abbr=on}} long and {{convert|0.5|to|2.5|mm|in|abbr=on}} wide. The tepals of the section Unguiculatis are {{convert|3|to|8.5|mm|in|abbr=on}} long and {{convert|1|to|3.5|mm|in|abbr=on}} wide. The labellum is about {{convert|5|to|25|mm|abbr=on}} long and {{convert|4|to|22|mm|in|abbr=on}} 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, but is not homologous to them;{{cite journal|author1=P.J. Rudall |author2=A. Eastman |year=2002|title=The questionable affinities of Corsia (Corsiaceae): evidence from floral anatomy and pollen morphology|journal=Botanical Journal of the Linnean Society|volume=138|issue=3|pages=315–324|doi=10.1046/j.1095-8339.2002.00024.x|doi-access=free}} 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.

File:Corsia ornata fruits.jpg

File:Corsia ornata seeds.jpg

After pollination (possibly by flies), the peduncles extend and a {{convert|3.5|cm|in|abbr=on}} long and slender cylindrical yellowish brown capsule fruit forms. The small dust-like seeds are about {{convert|1|to|3.2|mm|in|abbr=on}} long, {{convert|0.3|mm|in|abbr=on}} 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, [http://nt.ars-grin.gov/sbmlweb/OnlineResources/SeedsFruits/rptSeedsFruitsFamData.cfm?thisFamily=Corsiaceae Online version] {{Webarchive|url=https://web.archive.org/web/20071007001446/http://nt.ars-grin.gov/sbmlweb/OnlineResources/SeedsFruits/rptSeedsFruitsFamData.cfm?thisFamily=Corsiaceae |date=2007-10-07 }} Although the native habitat of Corsia is relatively calm, seed dispersal is presumed to be facilitated by wind (anemochory).C. Neinhuis, P. Ibisch: Corsiaceae, in: K. Kubitzki (Hrsg.): The Families and Genera of Vascular Plants, Vol. 3, Lilianae, p. 200, 1998, {{ISBN|3-540-64060-6}}

Species of Corsia are generally found in floodplains and mountain forests at altitudes of {{convert|400|to|2700|m|ft|abbr=on}} above sea level. They grow in humus-rich soils in shaded areas of high humidity among decaying leaves.

The center of diversity for the genus is New Guinea. All species are endemic to New Guinea (including the Bismarck Archipelago), the Solomon Islands, and Australia.

Like other members of Corsiaceae, Corsia species lack chlorophyll and are thus incapable of photosynthesis. Instead, they are myco-heterotrophs, relying exclusively on parasitizing arbuscular mycorrhizal fungi for nutrition.{{cite book|author=Christopher G. Morris|title=Academic Press dictionary of science and technology|publisher=Gulf Professional Publishing|year=1992|page=529|isbn =978-0-12-200400-1|url=https://books.google.com/books?id=nauWlPTBcjIC&q=Corsiaceae&pg=PA529}} Myco-heterotrophs were once mistakenly thought to be saprotrophic plants. It is now known that they do not obtain nourishment directly from decaying organic matter, instead they digest the hyphae 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, and Cotylanthera tenuis.{{citation needed|date = January 2012}}

File:CorsiaSpecIIHabitFullEditDB.jpg area of Papua New Guinea]]

Corsia is classified under the family Corsiaceae of the order Liliales. It is one of the three genera currently classified under Corsiaceae, the other two being Corsiopsis of China and Arachnitis of South America.{{cite journal|author1=Laura S. Domínguez |author2=Alicia Sérsic |year=2004|title=The southernmost myco-heterotrophic plant, Arachnitis uniflora: root morphology and anatomy |journal=Mycologia |volume=96|issue=5|pages=1143–1151 |url=http://www.mycologia.org/content/96/5/1143.full.pdf+html |doi=10.2307/3762096|jstor=3762096 |pmid=21148933 |hdl=11336/36710 |hdl-access=free }} It differs from the latter two in having several shoots arising from creeping rhizomes.{{cite journal|author=Dian-Xiang Zhang|year=2000|title=Addition to the Flora Reipublicae Popularis Sinicae: the family Corsiaceae|journal=Acta Phytotaxonomica Sinica|volume=38|issue=6|pages=578–581|language=Chinese|url=http://www.plantsystematics.com/qikan/manage/wenzhang/f990092.pdf }}

Corsia was first described in 1877 by the Italian naturalist Odoardo Beccari from specimens from New Guinea. He named it after the Marquis Bardo Corsi Salviati. It was classified under Burmanniaceae by the English botanist George Bentham in 1883 and grouped together with orchids (family Orchidaceae).

In 1938, Fredrik Pieter Jonker separated Arachnitis and Corsia from Burmanniaceae based on their strongly zygomorphic 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 Liliales) 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 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.{{cite journal |author1=Pierre L. Ibisch |author2=Christoph Neinhuis |author3=Patricia Rojas N. |year=1996 |title=On the biology, biogeography, and taxonomy of Arachnitis Phil. nom. cons. (Corsiaceae) in respect to a new record from Bolivia |journal=Willdenowia |volume=26 |issue=1–2 |pages=321–332 |issn=0511-9618 |url=http://www.bgbm.org/willdenowia/w-pdf/w26Ibisch+al.pdf |doi=10.3372/wi.26.2616 |s2cid=4002791 |access-date=2011-12-30 |archive-url=https://web.archive.org/web/20120426162953/http://www.bgbm.org/willdenowia/w-pdf/w26Ibisch+al.pdf |archive-date=2012-04-26 |url-status=dead }}

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 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 of Liliales, while the latter may be more closely related to Thismia and/or Burmannia of Dioscoreales.{{cite journal|author1=Ray Neyland |author2=Melissa Hennigan |year=2003|title=A phylogenetic analysis of large-subunit (26S) ribosome DNA sequences suggests that the Corsiaceae are polyphyletic|journal=New Zealand Journal of Botany|volume=41|issue=1|pages=1–11|doi=10.1080/0028825X.2003.9512828|s2cid=84392170 |doi-access=free|bibcode=2003NZJB...41....1N }}P. F. Stevens (2001 onwards). "[http://www.mobot.org/MOBOT/Research/APweb/orders/lilialesweb.htm#Corsiaceae 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.{{cite journal |author1=Michael F. Fay |author2=Mark W. Chase |author3=Nina Rønsted |author4=Dion S. Devey |author5=Yohan Pillon |author6=J. Chris Pires |author7=Gitte Petersen |author8=Ole Seberg |author9=Jerrold I. Davis |year=2006 |title=Phylogenetics of Liliales: summarized evidence from combined analyses of five plastid and one mitochondrial loci |journal=Aliso |volume=22 |pages=559–565 |url=http://ninaronsted.dk/page1/files/page1_6.pdf |access-date=2011-12-30 |archive-url=https://web.archive.org/web/20120426081800/http://ninaronsted.dk/page1/files/page1_6.pdf |archive-date=2012-04-26 |url-status=dead }}

Corsia contains two sections, Unguiculatis and Sessilis, with 25 species. They are listed below along with their distribution ranges:{{cite web | author= R. Govaerts |year=2011 | title= World Checklist of Corsiaceae | others= Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet | url= http://apps.kew.org/wcsp/ | accessdate=23 November 2011 }}{{cite web|url=http://www.theplantlist.org/browse/A/Corsiaceae/Corsia/|title=Corsia|year=2010|publisher=The Plant List Version 1.0|accessdate=29 December 2011}}{{cite web|author1=Barry J. Conn |author2=Roy Banla |author3=Linn Linn Lee |title=Plants of Papua New Guinea|publisher=Papua New Guinea National Herbarium and the National Herbarium of New South Wales|url=http://www.pngplants.org|accessdate=29 December 2011}}{{cite web |url=http://www.anbg.gov.au/cgi-bin/apni?TAXON_NAME=Corsia|title=Corsia |accessdate=29 December 2011 |website= Australian Plant Name Index (APNI), IBIS database|publisher = Centre for Plant Biodiversity Research, Australian Government, Canberra}}

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 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 P.Royen (Papua New Guinea)
• Corsia cordata Schltr. (Papua New Guinea)
• Corsia crenata J.J.Sm. (Indonesia)
• Corsia cyclopensisP.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 Schltr. (Northeast Papua New Guinea)
• Corsia viridopurpurea P.Royen (Papua New Guinea)
• Corsia wubungu P.Royen (Papua New Guinea)

{{Wikispecies}}

{{Commons category}}

• List of myco-heterotrophic genera

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{{Reflist|2}}

• P. Van Royen:Sertulum Papuanum 17th Corsiaceae of New Guinea and surrounding areas in: Webbia 27: pp. 223–255, 1972, {{ISSN|0083-7792}}
• Traudel Rübsamen: Morphologische, embryologische und systematische Untersuchungen an Burmanniaceae und Corsiaceae (Mit Ausblick auf die Orchidaceae-Apostasioideae) [Morphological, embryological and systematic studies of Burmanniaceae and Corsiaceae (With view on the Orchidaceae-Apostasioideae)], 1986, {{ISBN|3-443-64004-4}}
• Karl Schumann, Karl Lauterbach: Nachträge zur Flora der deutschen Schutzgebiete in der Südsee mit Ausschluss Samoa's und der Karolinen [Supplements to Flora of the German protectorates in the Pacific to the exclusion of Samoa's and the Carolinas], Leipzig, 1905, [http://www.botanicus.org/title.aspx?bibid=b11964832 Online version]
• R. Schlechter: Neue Corsiaceae Papuasiens [New Papuan Corsiaceae Parisiens], in: Botanical yearbooks for systematics, plant geography and plant history, Vol. 49, pp. 109–112, 1913, Stuttgart, [http://www.botanicus.org/page/218926 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, ([https://www.jstor.org/stable/2419691 Abstract Online])
• {{cite book |editor1-last=Merckx |editor1-first=Vincent |title=Mycoheterotrophy: the biology of plants living on fungi |url=https://link.springer.com/book/10.1007/978-1-4614-5209-6|date=2013 |publisher=Springer Science+Business Media |location=New York |isbn=978-1-4614-5208-9|last1= Merckx|first1=Vincent S. F. T.|last2=Freudenstein|first2=John V. |last3=Kissling|first3=Jonathan |display-authors=etal|chapter=Taxonomy and Classification|pages=19–101|doi=10.1007/978-1-4614-5209-6 |s2cid=259078590 |ref={{harvid|Merckx et al|2013}}}}

{{Taxonbar|from=Q138314}}

Category:Liliales genera

Category:Corsiaceae

Category:Parasitic plants

Category:Parasites of fungi

Category:Taxa named by Odoardo Beccari