Trithuria cowieana is a species of aquatic plant in the family Hydatellaceae endemic to the Northern Territory, Australia.
Description Vegetative characteristics Trithuria cowieana is an annual aquatic plant with linear, max. 75 mm long, and 0.3–0.4 mm wide leaves. The plant turns red, once it reaches the flowering stage. Generative characteristics It is a monoecious species with bisexual reproductive units ("flowers"). The reproductive units are produced on 2–110 mm long peduncles. They consist of 4–8(–10), 1.2–2.3 mm long, and (0.2)0.3–0.5(0.6) mm wide involucral bracts, as well as 20–40 carpels, and 1–3 stamens with red filaments. The fruit is 0.28–0.41 mm long. The reproductive units are likely to be self-pollinating.
Distribution It is endemic to the Northern Territory, Australia.
Taxonomy Trithuria cowieana D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall was described by Dmitry Dmitrievich Sokoloff, Margarita Vasilyena Remizowa, Terry Desmond Macfarlane, and Paula J. Rudall in 2008. The type specimen was collected at the edge of a swamp by C.R. Michell in Northern Marrawal Plateau, Nitmiluk National Park, Northern Territory, Australia on the 28th of March 2002.Trithuria cowieana D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall. (n.d.). Australian Plant Name Index (APNI). Retrieved November 2, 2024, from https://biodiversity.org.au/nsl/services/rest/name/apni/226467Sokoloff, 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. It is placed in the section Trithuria sect. Altofinia.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.
Etymology The specific epithet cowieana honours Ian D. Cowie.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.
Conservation The conservation status is Data Deficient.Northern Territory Government. (n.d.-b). Trithuria cowieana D.D.Sokoloff, Remizowa, T.D.Macfarl. & Rudall. FloraNT. Retrieved November 2, 2024, from https://eflora.nt.gov.au/factsheet?id=27700 It is known from three localities.
Ecology It occurs in swamps, and in sand along roads and vehicle tracks.
Phylogeny Trithuria cowieana split from Trithuria cookeana about 4 million years ago in the lower Pliocene.Lin, Q. (2014). Using a low-copy nuclear gene (phosphoglycerate kinase; PGK) to explore the phylogeny of the aquatic plant family Hydatellaceae (Nymphaeales) (Doctoral dissertation, University of British Columbia).
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