Trithuria inconspicua subsp. brevistyla
| Trithuria inconspicua subsp. brevistyla | |
|---|---|
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Order: | Nymphaeales |
| Family: | Hydatellaceae |
| Genus: | Trithuria |
| Species: | Cheeseman
|
| Subspecies: | T. i. subsp. brevistyla
|
| Trinomial name | |
| Trithuria inconspicua subsp. brevistyla | |
| |
| Trithuria inconspicua subsp. brevistyla is endemic to the South island of New Zealand[1] | |
| Synonyms[1] | |
Trithuria inconspicua subsp. brevistyla is a subspecies of Trithuria inconspicua in the family Hydatellaceae endemic to the South Island of New Zealand.[1]
Description
[edit]Vegetative characteristics
[edit]It is a 10–40 mm tall,[2][3] aquatic, perennial, rhizomatous herb with adventitious roots[3] as well as 8–37 mm long, and 0.4–0.6 mm wide leaves.[2]
Generative characteristics
[edit]Only female plants are known. Male reproductive structures have not been observed.[4][2] The 1–5, unisexual, female reproductive units ("flowers") consist of glabrous, terete, 1–6 mm long, and 0.3–0.4 mm wide stalks,[2] which do not elongate with maturity,[2][4][3] 2–4(–7) ovate, 1.6–4.0 mm long involucral bracts, and 9–25 carpels[2] with short stigmatic hairs. The globose to ovoid fruit[3][2][4][5] is 0.39–0.56 mm long, and 0.3–0.5 mm wide.[2] It is an apomictic species. Flowering occurs from January to February and fruiting occurs from March to May.[6][2]
Differentiation from Trithuria inconspicua subsp. inconspicua
[edit]It differs from the autonymous subspecies Trithuria inconspicua subsp. inconspicua in respect to the morphology of the reproductive structures (stalks not elongating with maturity,[2][4][3] short stigmatic hairs, and globose to ovoid fruits[3][2][4][5]). In addition, male reproductive structures are known from Trithuria inconspicua subsp. inconspicua,[5] whereas Trithuria inconspicua subsp. brevistyla is considered to be female only.[4][2]
Distribution
[edit]It is endemic to South Island, New Zealand.[2]
Taxonomy
[edit]It was published by Kerry Alison Ford in 2019.[2] 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.[7] Trithuria inconspicua is placed in Trithuria sect. Hydatella.[8]
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),[4] 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,[9][6][1][10] but others accept the designation as a separate species.[3][11]
Etymology
[edit]The subspecific epithet brevistyla, from the Latin brevis meaning "brief", and stylus meaning "pencil", refers to the short stigmatic hairs found in this subspecies.[6][10][2]
Conservation
[edit]It is classified as Nationally Endangered (E).[12] The total area of its habitat is ≤ 100 ha (1 km²).[11]
Ecology
[edit]It occurs in lakes[12] 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.[2]
References
[edit]- ^ a b c d e "Trithuria inconspicua subsp. brevistyla K.A.Ford". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 13 November 2024.
- ^ a b c d e f g h i j k l m n o p 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.
- ^ a b c d e f g 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)
- ^ a b c d e f g 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.
- ^ a b c 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
- ^ a b c 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
- ^ a b 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
- ^ a b 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.
- ^ a b Johnson, P. N., Lee, W. G., & Khan, S. (2022). Wetlands of the Otago Region.