Trithuria polybracteata explained

Trithuria polybracteata is a species of plant in the family Hydatellaceae endemic to Western Australia.^[1]

Description

Vegetative characteristics

It is an annual herb with linear, basal, up to 15 mm long, and 0.5 mm wide leaves.

Generative characteristics

It is a dioecious species with unisexual reproductive units ("flowers"). Female plants produce up to 20 reproductive units with 15–27 mm long peduncles, 12–25(–30) bracts, and many carpels with up to 1.5 mm long stigmatic hairs. Male plants produce reproductive units with 10–11 mm long peduncles, 5–9 bracts and 9–11 stamens. The anthers are 1.5–2.0 mm long. The 0.2–0.25 mm long fruits with a three-ribbed pericarp bear smooth seeds. Being dioecious, it is an obligate xenogamous species.

Distribution

It is endemic to Western Australia.

Taxonomy

It was published by Dmitry Dmitrievich Sokoloff, Margarita Vasilyena Remizowa, Terry Desmond Macfarlane, and Paula J. Rudall in 2008 based on previous work by David Alan Cooke.^[2] The type specimen was collected by J.H.Willis in North Kimberley on the 26th of May 1984.^[3] It is placed in Trithuria sect. Hamannia.^{[4] [5]}

Etymology

The specific epithet polybracteata, from poly- meaning "many",^[6] and -bracteata meaning "bearing bracts",^[7] means bearing many bracts.
It has numerous bracts surrounding the reproductive units.

Conservation

Under the Biodiversity Conservation Act 2016, it is classified as a Priority 1: Poorly-known species.^{[8] [9]} It is only known from a single locality.^[10]

Ecology

It is known to occur in springs growing together with Utricularia. It has been speculated to show some degree of tolerance towards salinity.^[11]

Notes and References

1. 77088642-1 . Trithuria polybracteata D.A.Cooke ex D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall . 10 November 2024.
2. 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.
3. Trithuria polybracteata | International Plant Names Index. (n.d.). Retrieved November 11, 2024, from https://www.ipni.org/n/77088642-1
4. Iles, W. J., Rudall, P. J., Sokoloff, D. D., Remizowa, M. V., Macfarlane, T. D., Logacheva, M. D., & Graham, S. W. (2012). Molecular phylogenetics of Hydatellaceae (Nymphaeales): Sexual‐system homoplasy and a new sectional classification. American Journal of Botany, 99(4), 663-676.
5. 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.
6. Hermsen, E. J. (n.d.). Greek & Latin in Botanical Terminology. Digital Atlas of Ancient Life. Retrieved November 11, 2024, from https://www.digitalatlasofancientlife.org/learn/embryophytes/botanical-terminology/
7. Burnham, R. J. & University of Michigan. (2013, July 24). Amphicarpaea bracteata. CLIMBERS Censusing Lianas in Mesic Biomes of Eastern RegionS. Retrieved November 11, 2024, from https://climbers.lsa.umich.edu/amphicarpaea-bracteata/
8. Trithuria polybracteata D.A.Cooke ex D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall. (n.d.). Atlas of Living Australia. Retrieved November 10, 2024, from https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2918284
9. Western Australian Herbarium & Department of Biodiversity, Conservation and Attractions. (n.d.-b). Trithuria polybracteata D.D.Sokoloff, M.V.Remizowa, T.Macfarlane & Rudall. Florabase—the Western Australian Flora. Retrieved November 12, 2024, from https://florabase.dbca.wa.gov.au/browse/profile/34396
10. Iles, W. J. D. (2013). The phylogeny and evolution of two ancient lineages of aquatic plants (Doctoral dissertation, University of British Columbia).
11. Sokoloff, D. D., Remizowa, M. V., Macfarlane, T. D., Yadav, S. R., & Rudall, P. J. (2011). Hydatellaceae: a historical review of systematics and ecology. Rheedea, 21(2), 115-138.