Eurychorda Explained

Eurychorda is a monotypic genus of flowering plants in the family Restionaceae formally described in 1998.[1] [2] The only known species, Eurychorda complanata, commonly known as the flat cord-rush, is endemic to Australia.[3] It is characterised by flattened stems and reduced, sheathing leaves.

Description

A perennial or rhizomatous geophyte herb, Eurychorda complanata exhibits a graminoid growth form with tufted or shortly creeping rhizomes, and erect culms ranging from in height and in diameter.[4] [5] [6] Leaves are reduced pale, glabrous sheaths along the stem with acute apices, approximately long.[4] It has terminal inflorescences of spikelets, typically 5-20, arranged in a narrow panicle with shorter bracts.[4] [6] E. complanata is dioecious.[4] Male spikelets are ovate to globose, about long, with many flowers, while female spikelets are elliptic, approximately long, usually pedicellate, and have fewer flowers.[4] Both male and female flowers possess four tepals.[4] It flowers in summer (November, December, January, February) and has dry dehiscent capsule fruit.[4]

Habitat and distribution

Eurychorda complanata thrives in waterlogged peaty vegetation from sea level to sub-alpine areas and is a common species in button grass sedgeland communities.[6] It is common in Tasmania but its distribution extends across south-eastern Australia (Tasmania, Victoria, New South Wales, Queensland, South Australia).[4]

Taxonomy

Eurychorda complanata belongs to the family Restionaceae within the order Poales.[7] It was first identified in 1810 by Robert Brown in Prodromus Florae Novae Hollandiae.[8] [9] The species was then formally described and named in 1998 by Barbara Gillian Briggs & Lawrence Alexander Sidney Johnson.[10] The specific epiphet 'complanata' signifies its flattened morphology.

Threats and conservation

This species is rare in South Australia and listed as vulnerable due to habitat loss and degradation.[11] It is not listed as a threatened species elsewhere in its distribution.

Notes and References

  1. Briggs, Barbara Gillian & Johnson, Lawrence Alexander Sidney. 1998. Telopea 7: 357.
  2. http://www.tropicos.org/Name/100190952 Tropicos, Eurychorda B.G.Briggs & L.A.S.Johnson
  3. http://apps.kew.org/wcsp/namedetail.do?name_id=244938 Kew World Checklist of Selected Plant Families
  4. Faltser . Daniel . Gallagher, Rachael . Wenk, Elizabeth H. . et al . AusTraits, a curated plant trait database for the Australian flora . Scientific Data . 2021 . 8 . 1 . 254 . 10.1038/s41597-021-01006-6 . 34593819 . 8484355 . 2021NatSD...8..254F . 29 February 2024. 2440/133879 . free .
  5. Web site: Eurychorda complanata (R.Br.) B.G.Briggs & L.A.S.Johnson . Royal Botanic Gardens Kew: Plants of the World Online . 28 February 2024.
  6. Web site: Jordan . Greg . Eurychorda complanata . Key to Tasmanian Vascular Plants . 28 February 2024.
  7. Web site: Eurychorda complanata . Australian Plant Census . APC.
  8. Web site: Eurychorda complanata . APNI . 29 February 2024.
  9. Book: Brown . Robert . Prodromus Florae Novae Hollandiae . 27 March 1810 . London . 245 . 29 February 2024.
  10. B.G Briggs & L.A.S Johnson . New genera and species of Australian Restionaceae (Poales) . Telopea . 29 May 1998 . 7 . 4 . 359 . 10.7751/telopea19982005 . 29 February 2024.
  11. Web site: Eurychorda complanata (Restionaceae) Flat Cord-rush . Seeds of South Australia Conservation Centre . 28 February 2024.