Trithuria

Trithuria
Complete Trithuria submersa specimen
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Order: Nymphaeales
Family: Hydatellaceae
U. Hamann
Genus: Trithuria
Hook.f.
Type species
Trithuria submersa
Species

See here

     It is native to India, Australia, and New Zealand
Synonyms
  • Hydatella Diels
  • Juncella F.Muell. ex Hieron.

Trithuria is a genus of small ephemeral aquatic herb that represent the only members of the family Hydatellaceae found in India, Australia, and New Zealand. Almost all described species of Trithuria are found in Australia, with the exception of T. inconspicua and T. konkanensis, from New Zealand and India respectively. Until DNA sequence data and a reinterpretation of morphology proved otherwise, these plants were believed to be monocots related to the grasses (Poaceae). They are unique in being the only plants besides two members of Triuridaceae (Lacandonia schizmatica and L. braziliana) in which the stamens are centred and surrounded by the pistils; in Hydatellaceae the resulting 'flowers' may instead represent condensed inflorescences or non-flowers.

These diminutive, superficially moss-like, aquatic plants are the closest living relatives of a clade comprising two closely related water-lily families Nymphaeaceae and Cabombaceae. Together, these three families compose the order Nymphaeales in the APG III system of flowering plant classification. Trithuria (Hydatellaceae) diverged from the rest of Nymphaeales soon after Nymphaeales diverged from its sister taxon, although the crown clade evolved relatively recently, in the early Miocene (~19 Ma;). The order as a whole is the sister group of all flowering plants except Amborellales.

Trithuria exhibits a remarkable similarity to Centrolepis and species of both genera were mistaken for members of the other genus.

Description

Flowering Trithuria submersa
Trithuria inconspicua
Botanical illustration of Trithuria australis

Plants are submerged and emergent aquatic plants, rooted in the substrate below the water. They are tiny plants, just a few cm tall. Most species are ephemeral aquatics that flower in vernal pools when the water draws down, but several species are submerged perennials found in shallow lakes. The simple leaves are concentrated basally around a short stem. Individual species are cosexual (with several types of hermaphroditic conditions) or dioecious, and are either wind-pollinated (anemophilous) or self-pollinating (autogamous). Two predominantly apomictic species are also known. Flower-like reproductive units are composed of small collections of minute stamen- and/or pistil-like structures that may each represent very reduced individual flower, so that the reproductive units may be pseudanthia. The non-fleshy fruits are follicles or achenes. Hydatellaceae are unusual among angiosperms in allocating nutrients to the embryo before fertilization. In all other flowering plants, nutrient provisioning is known to occur only after fertilization. This trait is similar to gymnosperms, although in gymnosperms the nutrients come from the gametophyte rather than maternal tissue.

Cytology

The diploid chromosome count of Trithuria inconspicua subsp. inconspicua is 2n = c. 24. The diploid chromosome count of Trithuria submersa is 2n = 56. The diploid chromosome count of the tetraploid species Trithuria konkanensis 2n = 40. The diploid chromosome count of Trithuria australis is 2n = 14.

Taxonomy

The genus Trithuria Hook.f. was described by Joseph Dalton Hooker in 1858 with the type species Trithuria submersa Hook.f. It has two synonyms: In 1888 the genus Juncella F.Muell. ex Hieron. was described without a type designation by Georg Hans Emmo Wolfgang Hieronymus based on previous work by Ferdinand von Mueller. Mueller had invalidly published the nomen invalidum and nomen nudum Juncella tasmanica F.Muell. in 1854. Juncella is a nomen illegitimum. In 1904 the genus Hydatella Diels was described by Friedrich Ludwig Emil Diels without a type designation, but the lectotype Hydatella australis Diels. has been designated in 2008. The genus Hydatella was synonymised with Trithuria in 2008.

Trithuria was initially placed in the family Centrolepidaceae Endl. (now synonymous with Restionaceae R.Br.), which is placed in the order Poales Small but it was separated as its own family Hydatellaceae U.Hamann by Ulrich Hamann in 1976 with Hydatella Diels as the type genus. Upon its separation, Hamann stated the new families affinity or placement were still obscure. The correct placement of the family became apparent in 2007, when it was identified as a basal angiosperm lineage. The family Hydatellaceae is now placed in the order Nymphaeales Salisb. ex Bercht. & J. Presl.. Alternatively, it is placed in a separate order Hydatellales Cronquist ex Reveal & Doweld validly published by James Lauritz Reveal and Alexander Borissowitsch Doweld in 1999 based on previous work by Arthur Cronquist (see the Cronquist system). This is however not widely accepted, as the order Hydatellales is mostly treated as a synonym of Nymphaeales.

Etymology

The generic name Trithuria is derived from the Greek words τρεις treis meaning "three", and θυρις thyris meaning "window". It references the dehiscence of the capsule fruit.

Species

Trithuria has 13 species, although species diversity in the family has probably been substantially underestimated.

Phylogeny of Trithuria
sect. Altofinia

T. cookeana

T. cowieana

sect. Hamannia

T. polybracteata

T. konkanensis

T. lanterna

sect. Trithuria

T. occidentalis

T. bibracteata

T. submersa

sect. Hydatella

T. austinensis

T. australis

T. filamentosa

T. inconspicua

  1. Trithuria austinensis D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall Western Australia
  2. Trithuria australis (Diels) D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall - Western Australia
  3. Trithuria bibracteata Stapf ex D.A.Cooke - Western Australia
  4. Trithuria cookeana D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall - Northern Territory of Australia
  5. Trithuria cowieana D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall - Northern Territory
  6. Trithuria filamentosa Rodway - Tasmania
  7. Trithuria fitzgeraldii D.D.Sokoloff, I.Marques, T.D.Macfarl., Rudall & S.W.Graham - Western Australia
  8. Trithuria inconspicua Cheeseman - North Island of New Zealand
    Trithuria inconspicua subsp. brevistyla K.A.Ford - endemic to South Island, New Zealand
  9. Trithuria konkanensis S.R.Yadav & Janarth. - Maharashtra
  10. Trithuria lanterna D.A.Cooke - Northern Territory, Western Australia, Queensland
  11. Trithuria occidentalis Benth. - Western Australia
  12. Trithuria polybracteata D.A.Cooke ex D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall - Western Australia
  13. Trithuria submersa Hook.f. - Western Australia, South Australia, Victoria, New South Wales, Tasmania

Distribution and habitat

It is native to India, Australia, and New Zealand, where it occurs in seasonally dry aquatic environments as annuals, or more rarely in permanently inundated habitats as perennial plants.

Conservation

The IUCN conservation status of Trithuria lanterna is Least Concern (LC). Trithuria inconspicua is critically endangered.

References

  1. 1 2 3 "Trithuria Hook.f." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 17 November 2024.
  2. 1 2 Kew World Checklist of Selected Plant Families
  3. ↑ Marques, Isabel; Montgomery, Sean A.; Barker, Michael S.; Macfarlane, Terry D.; Conran, John G.; Catalán, Pilar; Rieseberg, Loren H.; Rudall, Paula J.; Graham, Sean W. (2016-04-01). "Transcriptome-derived evidence supports recent polyploidization and a major phylogeographic division in Trithuria submersa (Hydatellaceae, Nymphaeales)". New Phytologist. 210 (1): 310–323. Bibcode:2016NewPh.210..310M. doi:10.1111/nph.13755. ISSN 1469-8137. PMID 26612464.
  4. 1 2 3 4 5 6 7 8 Dmitry D. Sokoloff, Margarita V. Remizowa, Terry D. Macfarlane, and Paula J. Rudall. 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.
  5. ↑ Yadav SR, Janarthanam MK. 1995 Trithuria konkanensis (Hydatellaceae), eine neue Art aus Indien. Aqua Planta 20. (3): 91-97 (1995).
  6. ↑ Rudall, Paula J. (February 4, 2016). "Inside-out flowers of Lacandonia brasiliana (Triuridaceae) provide new insights into fundamental aspects of floral patterning". PeerJ. 4 e1653. doi:10.7717/peerj.1653. PMC 4748704. PMID 26870611.
  7. ↑ Else Marie Friis & Peter Crane (15 March 2007), "Botany: New home for tiny aquatics", Nature, 446 (7133): 269–270, Bibcode:2007Natur.446..269F, doi:10.1038/446269a, PMID 17361167
  8. ↑ Iles, William J D; Lee, Christopher; Sokoloff, Dmitry D; Remizowa, Margarita V; Yadav, Shrirang R; Barrett, Matthew D; Barrett, Russell L; Macfarlane, Terry D; Rudall, Paula J; Graham, Sean W (2014). "Reconstructing the age and historical biogeography of the ancient flowering-plant family Hydatellaceae (Nymphaeales)". BMC Evolutionary Biology. 14 (1). Springer Science and Business Media LLC: 102. Bibcode:2014BMCEE..14..102I. doi:10.1186/1471-2148-14-102. ISSN 1471-2148. PMC 4030046. PMID 24884487.
  9. ↑ Sokoloff, D. D., Remizowa, M. V., Linder, H. P., & Rudall, P. J. (2009). "Morphology and development of the gynoecium in Centrolepidaceae: the most remarkable range of variation in Poales." American Journal of Botany, 96(11), 1925-1940.
  10. ↑ Smissen, Rob D.; Ford, Kerry A.; Champion, Paul D.; Heenan, Peter B. (2019). "Genetic variation in Trithuria inconspicua and T. filamentosa (Hydatellaceae): a new subspecies and a hypothesis of apomixis arising within a predominantly selfing lineage". Australian Systematic Botany. CSIRO Publishing. doi:10.1071/sb18013. ISSN 1030-1887. S2CID 91261563.
  11. ↑ Macfarlane, T.D.; Watson, L. & Marchant, N.G., eds. (2000). "Hydatellaceae U Hamann". FloraBase: Flora of Western Australian. Archived from the original on 14 July 2007. Retrieved 2013-11-15.
  12. ↑ Hydatellaceae are water lilies with gymnospermous tendencies
  13. ↑ Flora of New Zealand | Taxon Profile | Trithuria. (n.d.). Retrieved July 26, 2023, from https://www.nzflora.info/factsheet/taxon/Trithuria.html
  14. ↑ Remizowa, M. V., Sokoloff, D. D., Macfarlane, T. D., Yadav, S. R., Prychid, C. J., & Rudall, P. J. (2008). "Comparative pollen morphology in the early‐divergent angiosperm family Hydatellaceae reveals variation at the infraspecific level." Grana, 47(2), 81-100.
  15. ↑ Sokoloff, D. D., Marques, I., Macfarlane, T. D., Remizowa, M. V., Lam, V. K. Y., Pellicer, J., … Graham, S. W. (2019). Cryptic species in an ancient flowering-plant lineage (Hydatellaceae, Nymphaeales) revealed by molecular and micromorphological data. TAXON, 68(1), 1–19. doi:10.1002/tax.12026
  16. ↑ Juncella F.Muell. ex Hieron. (n.d.). The Australian National Species List (auNSL). Retrieved November 17, 2024, from https://biodiversity.org.au/nsl/services/rest/instance/apni/520743
  17. ↑ Juncella tasmanica | International Plant Names Index. (n.d.). Retrieved November 18, 2024, from https://www.ipni.org/n/129787-3
  18. ↑ Juncella tasmanica F.Muell. (n.d.). The Australian National Species List (auNSL). Retrieved November 18, 2024, from https://biodiversity.org.au/nsl/services/rest/name/apni/96340/api/apni-format
  19. 1 2 3 Hamann, U. (1976). Hydatellaceae—a new family of Monocotyledoneae. New Zealand Journal of Botany, 14(2), 193-196.
  20. ↑ Hydatella Diels. (n.d.). The Australian National Species List (auNSL). Retrieved November 17, 2024, from https://biodiversity.org.au/nsl/services/rest/name/apni/86441/api/apni-format
  21. 1 2 Jeffery M. Saarela1; et al. (15 March 2007), "Hydatellaceae identified as a new branch near the base of the angiosperm phylogenetic tree", Nature, 446 (7133): 312–315, Bibcode:2007Natur.446..312S, doi:10.1038/nature05612, PMID 17361182, S2CID 4415881{{citation}}: CS1 maint: numeric names: authors list (link)
  22. ↑ "Restionaceae R.Br". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 17 November 2024.
  23. ↑ Linder, H. P., & Rudall, P. J. (2005). Evolutionary history of Poales. Annu. Rev. Ecol. Evol. Syst., 36(1), 107-124.
  24. ↑ Hamann, Ulrich | International Plant Names Index. (n.d.). Retrieved November 17, 2024, from https://www.ipni.org/a/5-1
  25. ↑ "Hydatellaceae U.Hamann". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 17 November 2024.
  26. 1 2 WFO (2024): Nymphaeales Salisb. ex Bercht. & J. Presl. Published on the Internet;http://www.worldfloraonline.org/taxon/wfo-9000000354. Accessed on: 17 Nov 2024
  27. ↑ Doweld A.B. 2022. New names of fossil Nymphaeaceae and allied forms. Geophytology 52(1&2): 1–28.
  28. ↑ Reveal, J. L., & Doweld, A. B. (1999). Validation of Some Suprageneric Names in Magnoliophyta. Novon, 9(4), 549–553. https://doi.org/10.2307/3392163
  29. ↑ Manaaki Whenua – Landcare Research. (n.d.-b). Nymphaeales Salisb. ex Bercht. & J.Presl. Flora of New Zealand Online. Retrieved November 17, 2024, from https://www.nzflora.info/factsheet/taxon/Nymphaeales.html
  30. ↑ Reveal, J. L. (2012). An outline of a classification scheme for extant flowering plants. Phytoneuron, 37(1), 1-221.
  31. ↑ Reveal, J. L., & Chase, M. W. (2011). APG III: Bibliographical information and synonymy of Magnoliidae. Archived 2021-12-27 at the Wayback Machine Phytotaxa, 19, 71-134.
  32. ↑ Hooker, Joseph Dalton, Fitch, W. H., & Reeve Brothers. (1844). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror in the Years 1839-1843 :under the command of Captain Sir James Clark Ross (Vol. 3, Issue 2, pp. 78-79). Reeve Brothers. https://www.biodiversitylibrary.org/page/28467263
  33. ↑ Department for Environment and Water. (n.d.). Trithuria submersa (Hydatellaceae) | Seeds of South Australia - Species information. Retrieved July 26, 2023, from https://spapps.environment.sa.gov.au/SeedsOfSA/speciesinformation.html?rid=4619
  34. ↑ Sokoloff, Dmitry D.; Marques, Isabel; Macfarlane, Terry D.; Remizowa, Margarita V.; Lam, Vivienne K.Y.; Pellicer, Jaume; Hidalgo, Oriane; Rudall, Paula J.; Graham, Sean W. (2019-04-14). "Cryptic species in an ancient flowering-plant lineage (Hydatellaceae, Nymphaeales) revealed by molecular and micromorphological data". Taxon. 68 (1). Wiley: 1–19. Bibcode:2019Taxon..68....1S. doi:10.1002/tax.12026. ISSN 0040-0262.
  35. ↑ Sokoloff, Dmitry D.; Remizowa, Margarita V.; Beer, Anton S.; Yadav, Shrirang R.; Macfarlane, Terry D.; Ramsay, Margaret M.; Rudall, Paula J. (May 2013). "Impact of spatial constraints during seed germination on the evolution of angiosperm cotyledons: A case study from tropical Hydatellaceae (Nymphaeales)". American Journal of Botany. 100 (5): 824–843. doi:10.3732/ajb.1200620. PMID 23613353.
  36. ↑ Iles, Will; Rudall, Paula J.; Sokoloff, D. D.; Graham, Sean W (March 2012). "Molecular phylogenetics of Hydatellaceae (Nymphaeales): Sexual-system homoplasy and a new sectional classification". American Journal of Botany. 99 (4): 663–676. Bibcode:2012AmJB...99..663I. doi:10.3732/ajb.1100524. PMID 22473977.
  37. ↑ Taylor, M. L., Macfarlane, T. D., & Williams, J. H. (2010). Reproductive ecology of the basal angiosperm Trithuria submersa (Hydatellaceae). Annals of Botany, 106(6), 909-920.
  38. ↑ Brummitt, N. 2013. Trithuria lanterna. The IUCN Red List of Threatened Species 2013: e.T44392948A44408157. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T44392948A44408157.en. Accessed on 13 December 2024.
  39. ↑ Critically endangered Northland lake plant voted NZ's favourite plant 2024. (2024, November 5). Northland Regional Council. Retrieved December 13, 2024, from https://www.nrc.govt.nz/news/2024/november/critically-endangered-northland-lake-plant-voted-nz-s-favourite-plant-2024/