Trithuria inconspicua subsp. brevistyla
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 consist of glabrous, terete, 1–6 mm long, and 0.3–0.4 mm wide stalks, which do not elongate with maturity, 2–4 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. 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 de Lange & Mosyakin by Peter James de Lange and Sergei Leonidovich Mosyakin within the same year of the original publication, yet there appears to be no consensus for this decision. Trithuria brevistyla 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.