Nymphaea alba subsp. occidentalis is a subspecies of Nymphaea alba native to western and northern Europe.
Description Vegetative characteristics Nymphaea alba subsp. occidentalis is an aquatic, rhizomatous, perennial plant.Nymphaea alba subsp. occidentalis (Ostenf.) Hyl., a White Water-lily. (n.d.). Botanical Society of Britain & Ireland. Retrieved June 23, 2025, from https://fermanagh.bsbi.org/nymphaea-alba-subsp-occidentalis-hyl The relatively small leaf is 9–13 cm long. Generative characteristics The relatively small, 5–8(–12) cm wide flowers do not open widely.Mériaux, J. L. (2003). Guide pratique de détermination des plantes aquatiques à l'état végétatif du Bassin Artois-Picardie. p. 25. Agence de l'eau Artois-Picardie. Stamens are absent towards the upper end of the ovary. The gynoecium consists of 8–15 carpels.Schou, J. C., Moeslund, B., Weyer, K. v. d., Wiegleb, G., Lansdown, R. V., Holm, P., Baastrup-Spohr, L., Sand-Jensen, K. (2023). Aquatic Plants of Northern and Central Europe Including Britain and Ireland. pp. 62, 65. United States: Princeton University Press.
Taxonomy It was first described as Nymphaea alba var. occidentalis by Carl Hansen Ostenfeld in 1912. It was elevated to the rank of the subspecies Nymphaea alba subsp. occidentalis published by Nils Hylander in 1945. Some sources treat it as a synonym of Nymphaea alba,Nymphaea alba L., 1753 - Nymphéa blanc, Nénuphar blanc, Lys des étangs. (n.d.). Inventaire National Du Patrimoine Naturel. Retrieved June 23, 2025, from https://inpn.mnhn.fr/espece/cd_nom/109750/tab/taxoUSDA, Agricultural Research Service, National Plant Germplasm System. 2025. Germplasm Resources Information Network (GRIN Taxonomy). National Germplasm Resources Laboratory, Beltsville, Maryland. URL: https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomydetail?id=415688. Accessed 23 June 2025.Nymphaea alba subsp. occidentalis (Ostenf.) Hyl. (n.d.-b). GBIF | Global Biodiversity Information Facility. Retrieved June 23, 2025, from https://www.gbif.org/species/6712980Nymphaea alba L. (n.d.). Catalogue of Life. Retrieved June 23, 2025, from https://www.catalogueoflife.org/data/taxon/48696Nymphaea alba. (n.d.). Euro+Med-Plantbase. Retrieved June 23, 2025, from https://europlusmed.org/cdm_dataportal/taxon/8f1d60b9-607d-47ef-b4dd-209dc1995ee0/synonymy?highlight=fcf859c0-306f-4aa0-932f-c021fc08e9c4#fcf859c0-306f-4aa0-932f-c021fc08e9c4 but others accept it as a subspecies.Nymphaea alba subsp. occidentalis (Ostenf.) Hyl. (n.d.-d). World Flora Online. Retrieved June 23, 2025, from https://stage.worldfloraonline.org/taxon/wfo-0001427180;jsessionid=8B6DA02E462CEC096002F1B4BBC8FEC4Nymphaea alba subsp. occidentalis (Ostenf.) Hyl. (n.d.-c). NBN Atlas. Retrieved June 23, 2025, from https://species.nbnatlas.org/species/NHMSYS0000461113Nymphaea alba subsp. occidentalis. (n.d.). EPPO Global Database. Retrieved June 23, 2025, from https://gd.eppo.int/taxon/NYMAOPaul R Green, Irish Vascular Plant Data - Paul Green, National Biodiversity Data Centre, Ireland, Nymphaea alba subsp. occidentalis, accessed 23 June 2025, from https://maps.biodiversityireland.ie/Dataset/178/Species/43519 Within the subgenus Nymphaea subg. Nymphaea , it is placed in the section Nymphaea sect. Nymphaea. Etymology The subspecific epithet occidentalis means western.Eckel, P. M. (n.d.). A Grammatical Dictionary of Botanical Latin. Missouri Botanical Garden. Retrieved June 23, 2025, from https://www.mobot.org/mobot/latindict/keyDetail.aspx?keyWord=west
Ecology It occurs in small, nutrient poor aquatic habitats in ponds,Ervik, F. (2024, November 26). Smånøkkerose. Store Norske Leksikon. Retrieved June 23, 2025, from https://snl.no/sm%C3%A5n%C3%B8kkerose marsh pools, small lakes, and sheltered bays of larger lakes.Mountford, O., Clarke, S., Gowing, D., Rothero, E., & Wallace, H. (2018). Meadows and more: a botanical journal of five days on the Uists, Benbecula and Eriskay. Hebridean Naturalist, 18, 72-88.
Distribution It is native to Belgium, Denmark, Finland, France, the United Kingdom, Ireland, Norway, and Sweden.
Conservation It is very rare. In Sweden, it is classified as vulnerable (VU).ArtDatabanken 2015. Rödlistade arter i Sverige 2015. ArtDatabanken SLU, UppsalaAtlantnäckros Nymphaea alba subsp. occidentalis (Ostenf.) Hyl. (n.d.). SLU Artdatabanken. Retrieved June 23, 2025, from https://artfakta.se/taxa/1899/rodlistning In the United Kingdom, it is of national conservation concern.Amphlett, A. (2013, May). The Flora of the Cairngorms National Park A Rare Plant Register. Botanical Society of the British Isles.
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