Wikipedia

Trithuria occidentalis

Trithuria occidentalis is a species of plant in the family Hydatellaceae endemic to Western Australia.[2]

Trithuria occidentalis
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Order: Nymphaeales
Family: Hydatellaceae
Genus: Trithuria
Species:
T. occidentalis
Binomial name
Trithuria occidentalis
Trithuria occidentalis is endemic to Western Australia[2]
Synonyms[2]
  • Juncella occidentalis (Benth.) Hieron.
  • Hydatella dioica D.A.Cooke

Description

edit

Vegetative characteristics

edit

It is an annual,[3][1] 2-3 cm tall, aquatic herb with 2-3 cm long, and 1 mm wide, red, linear leaves.[4] The midveins of the leaves are prominent.[3]

Generative characteristics

edit

It is a dioecious species with unisexual reproductive units. It exhibits sexual dimorphism in respect to the number of bracts present in the reproductive units ("flowers").[5] The male reproductive units consist of 3 mm long, erect stalks with 2 lanceolate, 7-8 mm long bracts, as well as 8-10 stamens. The stamens consist of linear, 3 mm long, faintly yellow anthers, and 1 cm long filaments.[3] The female plants produce smaller reproductive units[4] with 8–9(–12)[5] 1.5-2.2mm long bracts enclosing 8-10 carpels.[4] The dehiscent fruit[5] bears seeds, which are sculptured.[4][5]

Distribution

edit

It is endemic to Western Australia,[2] where it is restricted to a small area north-east from Perth.[5]

Taxonomy

edit

Trithuria occidentalis Benth. was first described by George Bentham in 1878. Later synonyms include Juncella occidentalis (Benth.) Hieron. and Hydatella dioica D.A.Cooke.[2] The type specimen was collected by James Drummond[5][4][6] in Swan River, Western Australia.[5] It is placed in Trithuria sect. Trithuria.[7][8] The description of Hydatella dioica D.A.Cooke was based on a male individual of Trithuria occidentalis Benth.[5][9]

Etymology

edit

The specific epithet occidentalis means western.[10][11]

Conservation

edit

It is a threatened species.[12] Under the Western Australian Wildlife Conservation Act of 1950, it is declared as Rare Flora. According to the IUCN criteria, it is classified as Critically Endangered (CR).[4] It is classified as endangered both under the Environment Protection and Biodiversity Conservation Act 1999 and the Biodiversity Conservation Act 2016.[13][1] In 1982, about 1000 plants were recorded. By 2007, the number of recorded individuals had dropped below 200 plants.[4]

Ecology

edit

It occurs in seasonal swamps,[3] and shallow, winter-wet claypans.[4]

References

edit
  1. ^ a b c Trithuria occidentalis Benth. (n.d.). Atlas of Living Australia. Retrieved November 10, 2024, from https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2919853
  2. ^ a b c d e f "Trithuria occidentalis Benth". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 9 November 2024.
  3. ^ a b c d D.A.Cooke. Hydatella dioica, in (ed.), Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. https://profiles.ala.org.au/opus/foa/profile/Hydatella%20dioica [Date Accessed: 10 November 2024]
  4. ^ a b c d e f g h Department of Environment and Conservation (2012) Western Trithuria (Trithuria occidentalis) Interim Recovery Plan 2012–2017. Interim Recovery Plan No. 327. Department of Environment and Conservation, Western Australia.
  5. ^ a b c d e f g h Sokoloff, D. D., Remizowa, M. V., Macfarlane, T. D., & Rudall, P. J. (2008). Classification of the early‐divergent angiosperm family Hydatellaceae: One genus instead of two, four new species and sexual dimorphism in dioecious taxa. Taxon, 57(1), 179-200.
  6. ^ Type of Trithuria occidentalis Benth. [family HYDATELLACEAE]. (n.d.). JSTOR. Retrieved November 10, 2024, from https://plants.jstor.org/stable/10.5555/al.ap.specimen.bm000991248
  7. ^ Sokoloff, D. D., Remizowa, M. V., Macfarlane, T. D., Conran, J. G., Yadav, S. R., & Rudall, P. J. (2013). Comparative fruit structure in Hydatellaceae (Nymphaeales) reveals specialized pericarp dehiscence in some early–divergent angiosperms with ascidiate carpels. Taxon, 62(1), 40-61.
  8. ^ Iles, W. J. D. (2013). The phylogeny and evolution of two ancient lineages of aquatic plants (Doctoral dissertation, University of British Columbia).
  9. ^ Rudall, P. (n.d.). Tiny plants make a huge impact. Kew. Retrieved November 10, 2024, from https://www.kew.org/read-and-watch/tiny-plants-make-impact
  10. ^ Eggli, U., & Newton, L. E. (2010). Etymological Dictionary of Succulent Plant Names. p. 170. Springer.
  11. ^ A Grammatical Dictionary of Botanical Latin. (n.d.-d). Missouri Botanical Garden. Retrieved November 9, 2024, from http://www.mobot.org/mobot/latindict/keyDetail.aspx?keyWord=west
  12. ^ Western Australian Herbarium & Department of Biodiversity, Conservation and Attractions. (n.d.). Trithuria occidentalis Benth. Florabase—the Western Australian Flora. Retrieved November 10, 2024, from https://florabase.dbca.wa.gov.au/browse/profile/32658
  13. ^ Australian Government & Department of Climate Change, Energy, the Environment and Water. (n.d.). Trithuria occidentalis — Swan Hydatella. Species Profile and Threats Database. Retrieved November 10, 2024, from https://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=42224
Retrieved from "https://en.wikipedia.org/w/index.php?title=Trithuria_occidentalis&oldid=1256553382"