''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in horticultural trade. This was a huge genus, which used to contain more than 1,200 species - the second largest in the Orchidaceae after '' Bulbophyllum''. In 2004, it decreased by more than half when many species were moved into new genera.

Distribution

''Pleurothallis'' is a completely New World group, widespread across much of Mexico, Central America, South America and the West Indies.Kew World Checklist of Selected Plant Families, ''Pleurothallis''
/ref> Flora of North America lists one species in Florida ''(P. gelina)'' but this has now been transferred to a different genus, ''

Stelis ''Stelis'', or leach orchids, is a large genus of orchids, with perhaps 500 species. The generic name ''Stelis'' is the Greek word for ' mistletoe', referring to the epiphytic habit of these species. These mainly epiphytic (rarely lithophytic) ...

''. The center of diversity of the genus is in the high Andes, especially in the chain of cloud forests in

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

. ''Pleurothallis'' grows in dry or wet, tropical or temperate climates.

Description

As a group they show a huge range in vegetative form, terrestrial or epiphytic, and can be found as tall cane-like plants a metre or so high, clumped or trailing, pendent or climbing, erect or creeping, tufted and tiny, delicate moss-like species that can grow on the thinnest of twigs. But they have one common denominator: they all have two pollinia. They have reduced their pseudobulbs and instead, some species have thick succulent leaves. Their flowers are among the most diverse and unusual, although often very small, and specialize in using tiny insects such as gnats or small wasps for pollination.

Taxonomy

To bring some order in this extremely diverse genus, 29 subgenera and 25 sections had been created. Much of this work has been done by Dr. C. Luer of the Missouri Botanical Garden. A new analysis, based on DNA testing, confirmed on the whole the classification of the subtribe Pleurothallidinae, with however ''Pleurothallis'' as the main difference. New genetic insight broke up this huge genus and made it more consistent with the principles of

monophyletic 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 gro ...

genera and evolutionary relationships. Several times before, a splitting up has been attempted, but there were always too many intermediate forms. In 2004 the genera ''

Acianthera ''Acianthera'' is a genus of orchids native to the tropical parts of the Western Hemisphere, especially Brazil.de Melo, M. C., Borba, E. L., & Paiva, E. A. S. (2010)Morphological and histological characterization of the osmophores and nectaries ...

'', ''

Ancipitia ''Ancipitia'' is a genus of orchids originating from South America, currently consisting of 28 species. This genus was once considered part of ''Pleurothallis'' and, since publication in 2004 as a separate genus, is not yet fully accepted in all ...

'', '' Antilla'', ''

Apoda-prorepentia ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...

'', ''

Areldia ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...

'', ''

Atopoglossum ''Pleurothallis'' is a genus of orchids commonly called bonnet orchids. The genus name is derived from the Greek word , meaning "riblike branches". This refers to the rib-like stems of many species. The genus is often abbreviated as "Pths" in hor ...

'', ''

Brenesia ''Acianthera'' is a genus of orchids native to the tropical parts of the Western Hemisphere, especially Brazil.de Melo, M. C., Borba, E. L., & Paiva, E. A. S. (2010)Morphological and histological characterization of the osmophores and nectaries ...

'', ''

Crocodeilanthe ''Stelis'', or leach orchids, is a large genus of orchids, with perhaps 500 species. The generic name ''Stelis'' is the Greek (language), Greek word for 'mistletoe', referring to the epiphyte, epiphytic habit of these species. These mainly epip ...

'' were created, incorporating a large number of former ''Pleurothallis'' species. The subgenera ''Pleurothallis'' and ''Specklinia'' are becoming separate genera, and the subgenus ''Acuminatae'' might become the proposed genus '' Anathallis''. Other allied genera include ''

Dracula ''Dracula'' is a novel by Bram Stoker, published in 1897. As an epistolary novel, the narrative is related through letters, diary entries, and newspaper articles. It has no single protagonist, but opens with solicitor Jonathan Harker taking ...

'', '' Masdevallia'', ''

Restrepia ''Restrepia'', abbreviated Rstp in horticultural trade, is a small genus of 50orchids in the orchid family (Orchidaceae), closely related to ''Pleurothallis''. Named in honor of Don Jose Restrepo, it tends to be more showy than most other Pleur ...

'', and ''

''.Analysis of the DNA-Based Reclassification of the Pleurothallidinae
/ref>

Species

Pleurothallis crossota (Orchidaceae) (29426272544)

, Kew's

Plants of the World Online Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...

listed around 540 species in the genus. Selected species include:

References

* Luer, Carlyle; 1986 - Icones Pleurothallidinarum III: Systematics of ''Pleurothallis'' (Orchidaceae); Missouri Botanical Garden Press. * {{Taxonbar, from=Q29979 Pleurothallidinae genera