Geosiris

{{Short description|Genus of flowering plants}}

{{Automatic taxobox

| image = Geosiris aphylla imported from iNaturalist photo 2963263 on 14 September 2023.jpg

| image_caption = Geosiris aphylla

| parent_authority = Golblatt & J.C.Manning

| taxon = Geosiris

| authority = Baill.

| type_species = Geosiris aphylla

| type_species_authority = Baill.

| subdivision_ranks = Species

| subdivision = Geosiris aphylla

Geosiris albiflora

Geosiris australiensis

}}

Geosiris is a genus in the flowering plant family Iridaceae, first described in 1894. It was thought for many years to contain only one species, Geosiris aphylla, endemic to Madagascar. But then in 2010, a second species was described, Geosiris albiflora, from Mayotte Island in the Indian Ocean northwest of Madagascar.[http://apps.kew.org/wcsp/namedetail.do?name_id=328153 Kew World Checklist of Selected Plant Families]Goldblatt & J.C.Manning, Bothalia 40: 170 (2010). In 2017, a third species was found in Queensland, Australia, Geosiris australiensis.{{cite web |title=Geosiris australiensis B.Gray & Y.W.Low {{!}} Plants of the World Online {{!}} Kew Science |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77164635-1 |website=Plants of the World Online |access-date=3 October 2022 |language=en}}

Geosiris aphylla is sometimes called the "earth-iris." It is a small myco-heterotroph lacking chlorophyll and obtaining its nutrients from fungi in the soil. The genus name is derived from the Greek words geos, meaning "earth", and iris, referring to the Iris family of plants.{{cite book |author1=Manning, John |author2=Goldblatt, Peter |title=The Iris Family: Natural History & Classification |publisher=Timber Press |location=Portland, Oregon|pages=96–98 |year=2008|isbn=978-0-88192-897-6}}

Its rhizomes are slender and scaly, and stems are simple or branched. The leaves are alternate, but having no use, are reduced and scale-like. The flowers are light purple.

In 1939, F. P. JonkerF. P. Jonker, 1939, "Les Géosiridacées, une nouvelle famille de Madagascar" Recueil Trav. Bot. Néerl. 36:473-179 assigned Geosiris to its own family Geosiridaceae in Orchidales, and this was adopted in the Cronquist system,Arthur Cronquist, An Integrated Systems of Classification of Flowering Plants (Columbia University Press, 1981) p.1236 with a note that the family was closely related to Iridaceae or Burmanniaceae. The Angiosperm Phylogeny Group has since subsumed the family into Iridaceae; it is currently placed in the monotypic subfamily Geosiridoideae.{{cite journal |last1=Reeves |first1=G |last2=Chase |first2=MW |last3=Goldblatt |first3=P |last4=Rudall |first4=P |last5=Fay |first5=MF |last6=Cox |first6=AV |last7=Lejeune |first7=B |last8=Souza-Chies |first8=T |title=Molecular systematics of Iridaceae: evidence from four plastid DNA regions |pmid=21669639 |journal=American Journal of Botany |date=November 2001 |volume=88 |issue=11 |pages=2074–87 |doi=10.2307/3558433 |jstor=3558433 |doi-access= }}{{cite journal|last1=Goldblatt|first1=Peter|last2=Rodriguez|first2=Aaron|last3=Powell|first3=M. P.|last4=Davies|first4=Jonathan T.|last5=Manning|first5=John C.|last6=van der Bank|first6=M.|last7=Savolainen|first7=Vincent|title=Iridaceae 'Out of Australasia'? Phylogeny, Biogeography, and Divergence Time Based on Plastid DNA Sequences|url=https://www.nceas.ucsb.edu/~davies/pdfs/Goldblatt%20et%20al.%202008.pdf|journal=Systematic Botany|volume=33|issue=3|year=2008|pages=495–508|issn=0363-6445|doi=10.1600/036364408785679806|s2cid=1803832|access-date=2020-01-17|archive-date=2016-03-04|archive-url=https://web.archive.org/web/20160304191342/https://www.nceas.ucsb.edu/~davies/pdfs/Goldblatt%20et%20al.%202008.pdf|url-status=dead}}