Trithuria inconspicua subsp. brevistyla

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Trithuria inconspicua subsp. brevistyla
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Order: Nymphaeales
Family: Hydatellaceae
Genus: Trithuria
Section: Trithuria sect. Hydatella
Species:
Cheeseman
Subspecies:
T. i. subsp. brevistyla
Trinomial name
Trithuria inconspicua subsp. brevistyla
South Island New Zealand.png
Trithuria inconspicua subsp. brevistyla is endemic to the South island of New Zealand [1]
Synonyms [1]

Trithuria brevistyla (K.A.Ford) de Lange & Mosyakin

Contents

Trithuria inconspicua subsp. brevistyla is a subspecies of Trithuria inconspicua in the family Hydatellaceae endemic to the South Island of New Zealand. [1]

Description

Vegetative characteristics

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

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

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

It is endemic to South Island, New Zealand. [2]

Taxonomy

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

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

It is classified as Nationally Endangered (E). [12] The total area of its habitat is ≤ 100 ha (1 km2). [11]

Ecology

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

  1. 1 2 3 4 5 "Trithuria inconspicua subsp. brevistyla K.A.Ford". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 13 November 2024.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 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.
  3. 1 2 3 4 5 6 7 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)
  4. 1 2 3 4 5 6 7 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.
  5. 1 2 3 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
  6. 1 2 3 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
  7. Trithuria inconspicua subsp. brevistyla | International Plant Names Index. (n.d.). Retrieved November 13, 2024, from https://www.ipni.org/n/77200751-1
  8. 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.
  9. 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
  10. 1 2 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
  11. 1 2 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.
  12. 1 2 Johnson, P. N., Lee, W. G., & Khan, S. (2022). Wetlands of the Otago Region.