| Trithuria inconspicua subsp. brevistyla | |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Order: | Nymphaeales |
| Family: | Hydatellaceae |
| Genus: | Trithuria |
| Species: | T. inconspicua Cheeseman |
| Subspecies: | T. i. subsp. brevistyla |
| Trinomial name | |
| Trithuria inconspicua subsp. brevistyla K.A.Ford | |
| |
| Trithuria inconspicua subsp. brevistyla is endemic to the South island of New Zealand | |
| Synonyms | |
Trithuria inconspicua subsp. brevistyla is a subspecies of Trithuria inconspicua in the family Hydatellaceae endemic to the South Island of New Zealand.
Description
Vegetative characteristics
It is a 10–40 mm tall, aquatic, perennial, rhizomatous herb with adventitious roots as well as 8–37 mm long, and 0.4–0.6 mm wide leaves.
Generative characteristics
Only female plants are known. Male reproductive structures have not been observed. The 1–5, unisexual, female reproductive units ("flowers") consist of glabrous, terete, 1–6 mm long, and 0.3–0.4 mm wide stalks, which do not elongate with maturity, 2–4(–7) ovate, 1.6–4.0 mm long involucral bracts, and 9–25 carpels with short stigmatic hairs. The globose to ovoid fruit is 0.39–0.56 mm long, and 0.3–0.5 mm wide. It is an apomictic species. Flowering occurs from January to February and fruiting occurs from March to May.
Differentiation from Trithuria inconspicua subsp. inconspicua
It differs from the autonymous subspecies Trithuria inconspicua subsp. inconspicua in respect to the morphology of the reproductive structures (stalks not elongating with maturity, short stigmatic hairs, and globose to ovoid fruits). In addition, male reproductive structures are known from Trithuria inconspicua subsp. inconspicua, whereas Trithuria inconspicua subsp. brevistyla is considered to be female only.
Distribution
It is endemic to South Island, New Zealand.
Taxonomy
It was published by Kerry Alison Ford in 2019. The type specimen was collected by K.A.Ford and R.D.Smissen in Mary Bay, Lake Hauroko, Southland, New Zealand on the 12th of March 2015. Trithuria inconspicua is placed in Trithuria sect. Hydatella.
It was elevated to the status of the separate species Trithuria brevistyla (K.A.Ford) de Lange & Mosyakin by Peter James de Lange and Sergei Leonidovich Mosyakin within the same year of the original publication (2019), yet there appears to be no consensus for this decision. Trithuria brevistyla (K.A.Ford) de Lange & Mosyakin is treated as a synonym of Trithuria inconspicua subsp. brevistyla K.A.Ford by several sources, but others accept the designation as a separate species.
Etymology
The subspecific epithet brevistyla, from the Latin brevis meaning "brief", and stylus meaning "pencil", refers to the short stigmatic hairs found in this subspecies.
Conservation
It is classified as Nationally Endangered (E). The total area of its habitat is ≤ 100 ha (1 km²).
Ecology
It occurs in lakes at depths of 0.3–2 m, where it grows in gravel, silt, and sand substrates. Rarely during dry seasons it becomes exposed above the water level.
References
- ^ "Trithuria inconspicua subsp. brevistyla K.A.Ford". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 13 November 2024.
- ^ 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.
- ^ de Lange, P.J. (2024): Trithuria brevistyla Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/trithuria-brevistyla/ (2024-11-13)
- ^ de LANGE, P. J., & Mosyakin, S. L. (2019). Trithuria brevistyla (Hydatellaceae), a new combination for the New Zealand endemic species from the South Island. Ukrainian Botanical Journal, 76(2), 95-100.
- ^ Manaaki Whenua – Landcare Research. (n.d.-a). Trithuria inconspicua Cheeseman subsp. inconspicua. Flora of New Zealand. Retrieved November 13, 2024, from https://www.nzflora.info/factsheet/taxon/Trithuria-inconspicua-subsp-inconspicua.html
- ^ Manaaki Whenua – Landcare Research. (n.d.-b). Trithuria inconspicua subsp. brevistyla K.A.Ford. Flora of New Zealand. Retrieved November 13, 2024, from https://www.nzflora.info/factsheet/taxon/Trithuria-inconspicua-subsp-brevistyla.html
- Trithuria inconspicua subsp. brevistyla | International Plant Names Index. (n.d.). Retrieved November 13, 2024, from https://www.ipni.org/n/77200751-1
- 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.
- Trithuria inconspicua subsp. brevistyla K.A.Ford. (n.d.). WFO Plant List | World Flora Online. Retrieved November 13, 2024, from https://wfoplantlist.org/taxon/wfo-0001368143-2024-06?page=1
- ^ Manaaki Whenua – Landcare Research. (n.d.). Trithuria inconspicua subsp. brevistyla K.A.Ford. Biota of New Zealand. Retrieved November 13, 2024, from https://biotanz.landcareresearch.co.nz/scientific-names/a1a1acd8-9b4f-4a14-a384-967383749bbe
- ^ de Lange, P. J., Gosden, J., Courtney, S. P., Fergus, A. J., Barkla, J. W., Beadel, S. M., ... & Michel, P. (2024). Conservation status of vascular plants in Aotearoa New Zealand, 2023. New Zealand Threat Classification Series, 43.
- ^ Johnson, P. N., Lee, W. G., & Khan, S. (2022). Wetlands of the Otago Region.
| Taxon identifiers | |
|---|---|
| Trithuria inconspicua subsp. brevistyla | |