''Brasenia'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

belonging to the family

Cabombaceae 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 APG IV system, Angiosperm Phylogeny Group IV system (2016). The family consists of ...

, consisting of one species, ''Brasenia schreberi'', commonly known as watershield. It is widely distributed in North America, the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

, northern South America (Venezuela, Guyana), eastern Asia (China, Japan, Korea,

Primorye Primorsky Krai, informally known as Primorye, is a federal subject (a krai) of Russia, part of the Far Eastern Federal District in the Russian Far East. The city of Vladivostok on the southern coast of the krai is its administrative center, an ...

), Australia, the

Indian Subcontinent The Indian subcontinent is a physiographic region of Asia below the Himalayas which projects into the Indian Ocean between the Bay of Bengal to the east and the Arabian Sea to the west. It is now divided between Bangladesh, India, and Pakista ...

, and parts of Africa.Kew World Checklist of Selected Plant Families
/ref> Junsai-asaproductinastore-march16-2014

''Brasenia'' is a perennial

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

with floating,

peltate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

leaves and

rhizomatous In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

stems. It is identified by its bright green leaves, small purple flowers that bloom from June through September, and a thick

mucilage Mucilage is a thick gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion, with the direction of their movement always opposite to that of the secretion of ...

that covers all of the underwater organs, including the underside of the leaves, stems, and developing buds. This mucilage may be an anti-herbivore defence trait, perhaps to deter snail grazing. It grows in shallow water of lakes, rivers and beaver ponds, particularly those with somewhat acidic water. Junsai held above Soup

Characteristics

Ponds along Attikamek Trail at Sault Ste

''Brasenia'' exhibits

wind pollination Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous plan ...

. The flowers have a two-day blooming period. On the first day, the functionally female, or pistillate flower, extends above the surface of the water and exposes the receptive stigmas. The flower then recedes below the water surface and on the following day emerges as a functionally male, or staminate flower. It is elevated higher than on the previous day and the anther-bearing filaments are extended beyond the female carpels. The anthers dehisce, releasing the pollen, and the flower is then withdrawn below the water where the fruit develops.

Cytology

The chloroplast genome is 158951 base pairs (bp) long.Gruenstaeudl, M., Nauheimer, L., & Borsch, T. (2017)
Plastid genome structure and phylogenomics of Nymphaeales: conserved gene order and new insights into relationships.
Plant systematics and evolution, 303, 1251-1270. The mitochondrial genome is composed of six parts ranging from 110220 bp to 628257 bp in size. The complete mitogenome is 1.49 mega–base-pair ( Mb) long.Shan, Y., Li, J., Duan, X., Zhang, X., & Yu, J. (2024)
Elucidating the multichromosomal structure within the ''Brasenia schreberi'' mitochondrial genome through assembly and analysis.
BMC genomics, 25(1), 422. The nuclear genome is 1170.4 Mb long.

Uses

''Brasenia'' is cultivated as a vegetable in China (where it is known as ''chúncài'' ) and where it is used in

Hangzhou Hangzhou, , Standard Mandarin pronunciation: ; formerly romanized as Hangchow is a sub-provincial city in East China and the capital of Zhejiang province. With a population of 13 million, the municipality comprises ten districts, two counti ...

in the well-known local speciality "West Lake Water Shield Soup" and in Japan. The mucilage it produces has been found to have anti-algal and anti-bacterial properties that may be useful as a natural weed control.

History

Species of ''Brasenia'' occurred during the interglacial of Europe, but like many other aquatic plant species and genera, it does not occur there now.

Name

''Brasenia schreberi'' has the common name watershield. The genus may commemorate the surgeon and Moravian missionary

Christoph Brasen Christoph is a male given name and surname. It is a German variant of Christopher. Notable people with the given name Christoph * Christoph Bach (1613–1661), German musician * Christoph Büchel (born 1966), Swiss artist * Christoph Dientze ...

(1738-1774), who was the first superintendent of the Moravian mission at Nain in

Labrador Labrador () is a geographic and cultural region within the Canadian province of Newfoundland and Labrador. It is the primarily continental portion of the province and constitutes 71% of the province's area but is home to only 6% of its populatio ...

.Pringle, James S. Possible eponymy of the generic name ''Brasenia'' Schreb. in Sida. vol. 16. no. 3. pp. 597-600. 1995

/ref>

Conservation

It is classified as least concern (LC) by The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

Red List. It is classified as vulnerable (VU) in South Korea.Kim, S. B. (Ed.). (2014)
Korean red list of threatened species.
National Institute of Biological Resources. The

NatureServe conservation status The NatureServe conservation status system, maintained and presented by NatureServe in cooperation with the Natural Heritage Network, was developed in the United States in the 1980s by The Nature Conservancy (TNC) as a means for ranking or categor ...

is G5 Secure. Under the

Flora and Fauna Guarantee Act 1988 The ''Flora and Fauna Guarantee Act 1988'', also known as the ''FFG Act'', is an act of the Victorian Parliament designed to protect species, genetic material and habitats, to prevent extinction and allow maximum genetic diversity within the Au ...

, it is categorised as Critically Endangered (CR).Royal Botanic Gardens Victoria. (n.d.-a). ''Brasenia schreberi'' J.F.Gmel. VicFlora Flora of Victoria. Retrieved December 7, 2024, from https://vicflora.rbg.vic.gov.au/flora/taxon/6d16f9c6-4db0-42a7-a4ab-595ec6116c4e

References

External links

Washington State Department of Ecology: ''Brasenia schreberi''Jepson Manual TreatmentUSDA Plants ProfilePhoto gallery
{{Authority control Nymphaeales genera Monotypic angiosperm genera Freshwater plants Japanese vegetables History of the Labrador Province of the Moravian Church Nymphaeales Cabombaceae