Trithuria australis explained

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

Description

Vegetative characteristics

Trithuria australis is an annual, submerged aquatic plant. The terete, pointed leaves are 20–25 mm long, and 0.3 mm wide.

Generative characteristics

The reproductive units ("flowers") are unisexual. Both female and male reproductive units are present on the same plant. The reproductive units are sessile or exhibit very short peduncles. The male reproductive unit has 3-8 stamens. The seed coat is brown and smooth. It is believed to be self-pollinating.^{[2] [3]}

Cytology

The chromosome count is 2n = 14.

Distribution

It is known from several populations occurring in the Western and Southwestern parts of the state Western Australia.

Taxonomy

Trithuria australis (Diels) D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall was first described as Hydatella australis Diels by Friedrich Ludwig Emil Diels in 1904.^[4] Later it was included in the genus Trithuria Hook.f. as Trithuria australis (Diels) D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall by Dmitry Dmitrievich Sokoloff, Margarita Vasilyena Remizowa, Terry Desmond Macfarlane & Paula J. Rudall in 2008.^[5] The type specimen was collected by L. Diels in Hamersley River, Western Australia in October 1901. It is included in Trithuria sect. Hydatella (Diels) D.D. Sokoloff, Iles, Rudall &S.W. Graham, of which it is the type species.

Etymology

The specific epithet australis means southern.^{[6] [7]}

Ecology

Habitat

It grows in swamps. It occurs sympatrically with Centrolepis.^[8]

Notes and References

1. 77088639-1 . Trithuria australis (Diels) D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall . 23 October 2024.
2. Iles, W. J. D. (2013). The phylogeny and evolution of two ancient lineages of aquatic plants (Doctoral dissertation, University of British Columbia).
3. Smissen, R. D., Ford, K. A., Champion, P. D., & Heenan, P. 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, 32(1), 1-11.
4. Diels, L., & Pritzel, E. (1905). Fragmenta Phytographiae Australiae occidentalis. Beiträge zur Kenntnis der Pflanzen Westaustraliens, ihrer Verbreitung und ihrer Lebens-Verhältnisse. In Botanische Jahrbücher fur Systematik, Pflanzengeschichte und Pflanzengeographie (Vol. 35, pp. 55–160). https://www.biodiversitylibrary.org/page/126540
5. 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. A Grammatical Dictionary of Botanical Latin. (n.d.-b). Retrieved October 28, 2024, from http://www.mobot.org/mobot/latindict/keyDetail.aspx?keyWord=australis
7. Daniels, R. (2020, May 30). Demystifying native plant names – an introduction. Australian Plants Society - NSW. Retrieved October 28, 2024, from https://resources.austplants.com.au/stories/demystifying-native-plant-names-an-introduction/
8. Taylor, Mackenzie Lorraine, "Developmental Evolution of the Progamic Phase in Nymphaeales. " PhD diss., University of Tennessee, 2011. https://trace.tennessee.edu/utk_graddiss/1031