Trithuria inconspicua

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Trithuria inconspicua
Trithuria inconspicua iNat2.jpg
Trithuria inconspicua growing in fine silica sand
Status NZTCS NC.svg
Nationally Critical (NZ TCS) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Order: Nymphaeales
Family: Hydatellaceae
Genus: Trithuria
Species:
T. inconspicua
Binomial name
Trithuria inconspicua
Cheeseman, 1906 [2]
Subspecies [3]
  • Trithuria inconspicua subsp. brevistyla K.A.Ford
  • Trithuria inconspicua subsp. inconspicua
LocationNewZealand.svg
Distribution of Trithuria inconspicua
Synonyms [3]

Hydatella inconspicua (Cheeseman) Cheeseman

Trithuria inconspicua is a small aquatic herb of the family Hydatellaceae that is only found in New Zealand. [4] [5]

Contents

Description

T. inconspicua partially buried under sediment. Photo by Jeremy Rolfe Trithuria inconspicua lake.jpg
T. inconspicua partially buried under sediment. Photo by Jeremy Rolfe

Trithuria inconspicua is a small (~4 cm) fresh water lily endemic to New Zealand. This lily grows in 5–7 meters of water and is restricted to the fresh water lakes of Northland and Fiordland regions of the North and South Island, respectively. Consisting of multiple 20–40 mm small tussocks and fibrous roots the plant is often partially buried under sediment or algae with only the leaf tips exposed. [1] As the plant is Monoicous individual male and female flowers are found on the same plant, however, in nature plants containing flowers of both sexes are rare. [6] The male flowers consist of bright red 10 mm long filaments, whilst the female flowers are yellow-brown and contain 5-10 styles bunched at the apex. [1]

There are two subspecies, Trithuria inconspicua subsp. inconspicua is found in dune lakes of Northland in the far north of the North Island, and T. inconspicua subsp. brevistyla is found in glacial lakes of the southern South Island (Smissen R.D., Ford K.A. Champion, P.D. and Heenan, P.B., Australian Systematic Botany 32(1): 1-11 (2019). http://www.nzflora.info/factsheet/taxon/Trithuria-inconspicua.html

The first flowering plant?

Based on molecular data from a single plastid gene (rbcL)T. inconspicua was originally believed to a monocot. [7] However, a more recent study using multiple genetic loci, supported by a subsequent re-evaluation of morphological characteristics, now places T. inconspicua as a sister group with the water lilies (Nymphaeales). [8] This new placement of T. inconspicua means only a single lineage of flowering plant is thought to be older, that being the woody New Caledonian shrub Amborella trichopoda . [9]

The predominant view that Amborella represents the oldest flowering plant was recently challenged in a study by Goremykini et al (2013), [10] who showed that when highly variable sites were removed from the dataset, T. inconspicua was consistently identified as the oldest angiosperm lineage. This proposal has attracted criticism from Drew et al (2014), who argued that the basal placement of T. inconspicua is an artifact of the variable site filtering method used by Goremykini et al (2013). [11] One of the main reasons why people are interested in this question is that placing T. inconspicua at the base of the angiosperm lineage would suggest the first angiosperms were soft bodied aquatic plants, rather than a woody terrestrial plants like Amborella . These competing theories have been given the light hearted monikers "wet and wild" and "dark and disturbed". [11] [12] [13]

Conservation status

Trithuria inconspicua is seriously threatened [1] due to the competition by the introduced bladder wort ( Utricularia gibba ) as well as other fresh water weeds.

Related Research Articles

<span class="mw-page-title-main">Flowering plant</span> Clade of seed plants that produce flowers

Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae, commonly called angiosperms. They include all forbs, grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs & vines, and most aquatic plants. The term "angiosperm" is derived from the Greek words ἀγγεῖον /angeion and σπέρμα / sperma ('seed'), meaning that the seeds are enclosed within a fruit. They are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. Angiosperms were formerly called Magnoliophyta.

<span class="mw-page-title-main">Malpighiales</span> Eudicot order of flowering plants

The Malpighiales comprise one of the largest orders of flowering plants, containing about 36 families and more than 16,000 species, about 7.8% of the eudicots. The order is very diverse, containing plants as different as the willow, violet, poinsettia, manchineel, rafflesia and coca plant, and are hard to recognize except with molecular phylogenetic evidence. It is not part of any of the classification systems based only on plant morphology. Molecular clock calculations estimate the origin of stem group Malpighiales at around 100 million years ago (Mya) and the origin of crown group Malpighiales at about 90 Mya.

<span class="mw-page-title-main">Saxifragales</span> Order of Eudicot flowering plants in the Superrosid clade

The Saxifragales (saxifrages) are an order of flowering plants (Angiosperms). They are an extremely diverse group of plants which include trees, shrubs, perennial herbs, succulent and aquatic plants. The degree of diversity in terms of vegetative and floral features makes it difficult to define common features that unify the order.

<span class="mw-page-title-main">Nymphaeales</span> Order of flowering plants

The Nymphaeales are an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae. It is one of the three orders of basal angiosperms, an early-diverging grade of flowering plants. At least 10 morphological characters unite the Nymphaeales. One of the traits is the absence of a vascular cambium, which is required to produce both xylem (wood) and phloem, which therefore are missing. Molecular synapomorphies are also known.

<span class="mw-page-title-main">Monocotyledon</span> Important clade of flowering plants

Monocotyledons, commonly referred to as monocots, are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and are classified as dicotyledons, or dicots.

<span class="mw-page-title-main">Nymphaeaceae</span> Family of plants

Nymphaeaceae is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains nine genera with about 70 known species. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on or emergent from the surface. Leaves are round, with a radial notch in Nymphaea and Nuphar, but fully circular in Victoria and Euryale.

<i>Amborella</i> Species of shrub

Amborella is a monotypic genus of understory shrubs or small trees endemic to the main island, Grande Terre, of New Caledonia in the southwest Pacific Ocean. The genus is the only member of the family Amborellaceae and the order Amborellales and contains a single species, Amborella trichopoda. Amborella is of great interest to plant systematists because molecular phylogenetic analyses consistently place it as the sister group to all other flowering plants.

<span class="mw-page-title-main">Cistaceae</span> Family of flowering plants comprising rock roses

The Cistaceae are a small family of plants known for their beautiful shrubs, which are profusely covered by flowers at the time of blossom. This family consists of about 170(-200) species in nine genera that are not very distinct, distributed primarily in the temperate areas of Europe and the Mediterranean basin, but also found in North America; a limited number of species are found in South America. Most Cistaceae are subshrubs and low shrubs, and some are herbaceous. They prefer dry and sunny habitats. Cistaceae grow well on poor soils, and many of them are cultivated in gardens.

<span class="mw-page-title-main">Limnanthaceae</span> Family of flowering plants

The Limnanthaceae are a small family of annual herbs occurring throughout temperate North America. There are eight species and nineteen taxa currently recognized. Members of this family are prominent in vernal pool communities of California. Some taxa have been domesticated for use as an oil seed crop. Some members are listed as threatened or endangered and have been the focus of disputes over development plans

<span class="mw-page-title-main">Cabombaceae</span> Family of flowering plants

The Cabombaceae are a family of aquatic, herbaceous flowering plants. A common name for its species is water shield. The family is recognised as distinct in the Angiosperm Phylogeny Group IV system (2016). The family consists of two genera of aquatic plants, Brasenia and Cabomba, totalling six species.

<span class="mw-page-title-main">Hydnoroideae</span> A subfamily of flowering plants comprising parasitic taxa

Hydnoroideae is a subfamily of parasitic flowering plants in the order Piperales. Traditionally, and as recently as the APG III system it given family rank under the name Hydnoraceae. It is now submerged in the Aristolochiaceae. It contains two genera, Hydnora and Prosopanche:

<span class="mw-page-title-main">Hydatellaceae</span> Family of flowering plants

Hydatellaceae are a family of small, aquatic flowering plants. The family consists of tiny, relatively simple plants occurring in Australasia and India. It was formerly considered to be related to the grasses and sedges, but has been reassigned to the order Nymphaeales as a result of DNA and morphological analyses showing that it represents one of the earliest groups to split off in flowering-plant phylogeny, rather than having a close relationship to monocots, which it bears a superficial resemblance to due to convergent evolution. The family includes only the genus Trithuria, which has at least 13 species, although species diversity in the family has probably been substantially underestimated.

<i>Trithuria</i> Genus of aquatic plants

Trithuria is a genus of small ephemeral aquatic herb that represent the only members of the family Hydatellaceae found in India, Australia, and New Zealand. All of the 13 formally characterized species of Trithuria are found in Australia, with the exception of T. inconspicua and T. konkanensis, which are found in New Zealand and India, respectively. Until DNA sequence data and a reinterpretation of morphology proved otherwise, these plants were believed to be monocots related to the grasses (Poaceae). They are unique in being the only plants besides two members of Triuridaceae in which the stamens are in the center of the flower while the pistils surround them; in Hydatellaceae the resulting 'flowers' may instead represent condensed inflorescences or non-flowers.

<i>Nymphaea odorata</i> Species of aquatic plant

Nymphaea odorata, also known as the American white waterlily, fragrant water-lily, beaver root, fragrant white water lily, white water lily, sweet-scented white water lily, and sweet-scented water lily, is an aquatic plant belonging to the genus Nymphaea. It can commonly be found in shallow lakes, ponds, and permanent slow moving waters throughout North America where it ranges from Central America to northern Canada. It is also reported from Brazil and Guyana.

<span class="mw-page-title-main">Basal angiosperms</span> Descendants of most extant flowering plants

The basal angiosperms are the flowering plants which diverged from the lineage leading to most flowering plants. In particular, the most basal angiosperms were called the ANITA grade, which is made up of Amborella, Nymphaeales and Austrobaileyales.

<span class="mw-page-title-main">Mesangiospermae</span> One of two clades of flowering plants

Mesangiospermae is a clade of flowering plants (angiosperms), informally called "mesangiosperms". They are one of two main groups of angiosperms. It is a name created under the rules of the PhyloCode system of phylogenetic nomenclature. There are about 350,000 species of mesangiosperms. The mesangiosperms contain about 99.95% of the flowering plants, assuming that there are about 175 species not in this group and about 350,000 that are. While such a clade with a similar circumscription exists in the APG III system, it was not given a name.

<i>Hydrostachys</i> Genus of flowering plants

Hydrostachys is a genus of about 22 species of flowering plants native to Madagascar and southern and central Africa. It is the only genus in the family Hydrostachyaceae. All species of Hydrostachys are aquatic, growing on rocks in fast-moving water. They have tuberous roots, usually pinnately compound leaves, and highly reduced flowers on dense spikes.

Pamela Soltis is an American botanist. She is a distinguished professor at the University of Florida, curator at the Florida Museum of Natural History, principal investigator of the Laboratory of Molecular Systematics and Evolutionary Genetics at the Florida Museum of Natural History, and founding director of the University of Florida Biodiversity Institute.

Douglas Soltis is a Distinguished Professor in the Laboratory of Molecular Systematics & Evolutionary Genetics, Florida Museum of Natural History and Department of Biology at the University of Florida. His research interests are in plant evolution and phylogeny, an area in which he has published extensively together with his wife Pamela Soltis and together they were the joint awardees of the 2006 Asa Gray Award. They are the principal investigators in the Soltis laboratory, where they both hold the rank of Distinguished Professor and are contributing authors of the Angiosperm Phylogeny Group.

<span class="mw-page-title-main">Pentapetalae</span> Group of eudicots known as core eudicots

In phylogenetic nomenclature, the Pentapetalae are a large group of eudicots that were informally referred to as the "core eudicots" in some papers on angiosperm phylogenetics. They comprise an extremely large and diverse group that accounting about 65% of the species richness of the angiosperms, with wide variability in habit, morphology, chemistry, geographic distribution, and other attributes. Classical systematics, based solely on morphological information, was not able to recognize this group. In fact, the circumscription of the Pentapetalae as a clade is based on strong evidence obtained from DNA molecular analysis data.

References

  1. 1 2 3 4 New Zealand Plant Conservation Network
  2. Cheeseman, T. F. (1906), Manual of the New Zealand Flora, New Zealand Government, p. 756, OCLC   688378960, Wikidata   Q5992016
  3. 1 2 "Trithuria inconspicua Cheeseman". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 18 May 2022.
  4. Kew World Checklist of Selected Plant Families
  5. Dmitry D. Sokoloff, Margarita V. Remizowa, Terry D. Macfarlane, and Paula J. Rudall. 2008. "Classification of the early-divergent angiosperm family Hydatellaceae: one genus instead of two, four new species and sexual dimorphism in dioecious taxa". Taxon57(1):179-200.
  6. Pledge, David H. 1974. "Some Observations on Hydatella Inconspicua (Cheesem.) Cheesem. (Centrolepidaceae)." New Zealand Journal of Botany 12 (4): 559–61.
  7. Michelangeli, Fabian A., Jerrold I. Davis, and Dennis Wm Stevenson. 2003. "Phylogenetic Relationships among Poaceae and Related Families as Inferred from Morphology, Inversions in the Plastid Genome, and Sequence Data from the Mitochondrial and Plastid Genomes." American Journal of Botany 90 (1): 93–106.
  8. Saarela, Jeffery M., Hardeep S. Rai, James A. Doyle, Peter K. Endress, Sarah Mathews, Adam D. Marchant, Barbara G. Briggs, and Sean W. Graham. 2007. "Hydatellaceae Identified as a New Branch near the Base of the Angiosperm Phylogenetic Tree." Nature 446 (7133): 312–15.
  9. Friis, Else Marie, and Peter Crane. 2007. "Botany: New Home for Tiny Aquatics." Nature 446 (7133): 269–70.
  10. Goremykini, V.V.; Nikiforova, S.V.; Biggs, P.J.; Zhong, B. de Lange, P.; Martin, W.; Woetzel, S.; Atherton, R.A., McLenachan, T.; Lockhart, P.J. 2013: The evolutionary root of flowering plants. Systematic Biology61 (1) 50–61.
  11. 1 2 Drew, Bryan T., Brad R. Ruhfel, Stephen A. Smith, Michael J. Moore, Barbara G. Briggs, Matthew A. Gitzendanner, Pamela S. Soltis, and Douglas E. Soltis. 2014. "Another Look at the Root of the Angiosperms Reveals a Familiar Tale." Systematic Biology 63 (3): 368–82.
  12. Feild, Taylor S., Nan Crystal Arens, James A. Doyle, Todd E. Dawson, and Michael J. Donoghue. 2004. "Dark and Disturbed: A New Image of Early Angiosperm Ecology." Paleobiology 30 (1): 82–107.
  13. Coiffard, C., B. Gomez, and F. Thevenard. 2007. "Early Cretaceous Angiosperm Invasion of Western Europe and Major Environmental Changes." Annals of Botany 100 (3): 545–53.