Trithuria inconspicua subsp. brevistyla | |
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Scientific classification ![]() | |
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 | |
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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]
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]
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]
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]
It is endemic to South Island, New Zealand. [2]
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]
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]
It is classified as Nationally Endangered (E). [12] The total area of its habitat is ≤ 100 ha (1 km2). [11]
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]