Megalachne

{{Short description|Genus of grasses}}

{{Distinguish|Megarachne}}

{{Speciesbox

|image =

|image_caption =

|display_parents = 4

|genus = Megalachne

|parent_authority = Steud.

|species = berteroniana

|authority = Steud.

|synonyms =

• Pantathera Phil.
• Bromus fernandezianus {{small|(Phil.) Skottsb.}}
• Bromus megalachne {{small|Pilg.}}
• Pantathera avenacea {{small|Hemsl.}}
• Pantathera fernandeziana {{small|Phil.}}

|synonyms_ref = [http://apps.kew.org/wcsp/synonomy.do?name_id=423301 Kew World Checklist of Selected Plant Families]{{cite web |title=Megalachne berteroniana Steud. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:325856-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=1 February 2025}}

}}

Megalachne is a genus of Chilean plants in the grass family, found only on the Juan Fernández Islands in the Pacific Ocean, part of the Republic of Chile.[https://www.biodiversitylibrary.org/page/186023#page/409/mode/1up Skottsberg, Carl Johan Fredrik & Pilger, Robert Knud Friedrich. 1920. Repertorium Specierum Novarum Regni Vegetabilis 16: 385-386] descriptions in Latin, commentary in German[https://www.biodiversitylibrary.org/page/31581671#page/179/mode/1up Matthei, Oscar R. 1974. Boletín de la Sociedad de Biología de Concepción 48: 171, f. 1a, c–e] in Spanish[https://www.biodiversitylibrary.org/page/345628#page/240/mode/1up Steudel, Ernst Gottlieb von. 1854. Synopsis Plantarum Glumacearum 1: 237] in Latin[http://www.kew.org/data/grasses-db/www/gen00370.htm Grassbase - The World Online Grass Flora] It contains a single species, Megalachne berteroniana.{{cite web |title=Megalachne Steud. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:325867-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=1 February 2025}}

A genetic analysis found it to be most closely related to the extinct Podophorus, also endemic to the Juan Fernández archipelago. This clade was in turn found to be nested within a paraphyletic Festuca, most closely related to F. pampeana of South America.{{Cite journal|last1=Moreno-Aguilar|first1=María Fernanda|last2=Arnelas|first2=Itziar|last3=Sánchez-Rodríguez|first3=Aminael|last4=Viruel|first4=Juan|last5=Catalán|first5=Pilar|date=2020-06-26|title=Museomics Unveil the Phylogeny and Biogeography of the Neglected Juan Fernandez Archipelago Megalachne and Podophorus Endemic Grasses and Their Connection With Relict Pampean-Ventanian Fescues|journal=Frontiers in Plant Science|volume=11|pages=819|doi=10.3389/fpls.2020.00819|issn=1664-462X|pmc=7333454|pmid=32754167|doi-access=free}}

Several species formerly included in genus Megalachne are now considered synonyms of species placed in other genera:

• Megalachne dantonii {{small|Penneck. & Gl.Rojas}} – synonym of Festuca dolichathera {{small|Röser & Tkach}}{{cite web |title=Megalachne dantonii Penneck. & Gl.Rojas |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77202240-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=1 February 2025}}
• Megalachne masafuerana (Skottsb. & Pilg.) Matthei – synonym of Festuca masafuerana {{small|(Skottsb. & Pilg.) Röser & Tkach}}{{cite web |title=Megalachne masafuerana (Skottsb. & Pilg.) Matthei |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:155827-2 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=1 February 2025}}
• Megalachne robinsoniana {{small|C.M.Peña}} – synonym of Festuca robinsoniana {{small|(C.M.Peña) Röser & Tkach}}{{cite web |title=Festuca robinsoniana (C.M.Peña) Röser & Tkach |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:77210905-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=1 February 2025}}
• Megalachne zeylanica {{small|Thwaites}} - synonym of Eriachne triseta {{small|Nees ex Steud.}}