Nymphaea pygmaea is a controversial species of perennial, aquatic herb in the family NymphaeaceaeNymphaea pygmaea W.T.Aiton. (n.d.). International Plant Names Index. Retrieved December 4, 2024, from https://www.ipni.org/n/605681-1 native to Asia.Borsch, T., Wiersema, J. H., Hellquist, C. B., Löhne, C., & Govers, K. (2014). Speciation in North American water lilies: evidence for the hybrid origin of the newly discovered Canadian endemic Nymphaea loriana sp. nov.(Nymphaeaceae) in a past contact zone. Botany, 92(12), 867-882.
Description
Vegetative characteristics It is a perennial, aquatic herb with erect, cylindrical, unbranched rhizomes without stolons. The obovate to orbicular, thick, 5.5–24 cm long, and 4.5–21 cm wide leaves with diverging basal lobes have an entire margin.Aiton, William, Aiton, William Townsend, Gowen, J. R., Whitfield, Richard Gullet, King’s College London., Physical Society (Guy’s Hospital), & St. Thomas’s Hospital. (1810). Hortus kewensis, or, A catalogue of the plants cultivated in the Royal Botanic Garden at Kew (Vol. 3, p. 293). Longman, Hurst, Rees, Orme, and Brown,. https://www.biodiversitylibrary.org/page/47853131 The upper leaf surface is green to purple. The petiole is slender. Generative characteristics The white,Hooker, J. D., Thomson, T. (1855). Flora Indica: Being a Systematic Account of the Plants of British India, Together with Observations on the Structure and Affinities of Their Natural Orders and Genera. p. 244. Vereinigtes Königreich: Pamplin. floating, 3–6 cm wide flower has four sepals with an obtuse apex and 5–17 petals with an obtuse apex. The androecium consists of 24–71 stamens. The gynoecium consists of 5-11 carpels. The globose fruit bears ellipsoid to ovoid, 1.9–3.6 mm long, and 1.3–2.6 mm wide seeds.
Cytology The chromosome count is 2n = 42Löve, Á. (1978). IOPB Chromosome Number Reports LXI. Taxon, 27(4), 375–392. http://www.jstor.org/stable/1220381 or 2n = 84. The ploidy level is 6x.Gupta, P. P. (1980). Cytogenetics of aquatic ornamentals. VI. Evolutionary trends and relationships in the genus Nymphaea. Cytologia, 45(1/2), 307-314.
Taxonomy It was first published as Castalia pygmaea Salisb. by Richard Anthony Salisbury in 1807. It was placed in the genus Nymphaea L. as Nymphaea pygmaea (Salisb.) W.T.Aiton by William Townsend Aiton published in 1811. It is widely regarded as a synonym of Nymphaea tetragona Georgi.Reid, M. K., Paterson, I. D., Coetzee, J. A., Gettys, L. A., & Hill, M. P. (2023). Know thy enemy: Investigating genetic contributions from putative parents of invasive Nymphaea mexicana hybrids in South Africa as part of efforts to develop biological control. Biological Control, 184, 105291.Nymphaea tetragona Georgi. (n.d.). Catalogue of Life (COL). Retrieved December 4, 2024, from http://www.catalogueoflife.org/data/taxon/486FMNymphaea pygmaea (Salisb.) Aiton. (n.d.). GBIF | Global Biodiversity Information Facility. Retrieved December 4, 2024, from https://www.gbif.org/species/3697746 The circumscription of Nymphaea tetragona in East Asia is however problematic and these problematic plants may be deserving of the status of a separate species Nymphaea pygmaea.Nymphaea tetragona Georgi. (n.d.-b). Flora of China @ efloras.org. Retrieved December 4, 2024, from http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200007090 There are several studies supporting this separate status.Naito, H., Kato, S., Shutoh, K., & Shiga, T. (2024). Morphological and phylogenetic analyses reveal the taxonomic distinctiveness between Nymphaea pygmaea and N. tetragona (Nymphaeaceae).Naito, H., & Shiga, T. (2024). Distribution of Nymphaea pygmaea and N. Tetragona (Nymphaeaceae) in Hokkaido, Sakhalin Island, and the Kuril Islands based on herbarium specimen records. Journal of Asia-Pacific Biodiversity, 17(1), 81-86. Position within Nymphaea Within the subgenus Nymphaea subg. Nymphaea, it is placed in the section Nymphaea sect. Chamaenymphaea,USDA, Agricultural Research Service, National Plant Germplasm System. 2024. Germplasm Resources Information Network (GRIN Taxonomy). National Germplasm Resources Laboratory, Beltsville, Maryland. URL: https://npgsweb.ars-grin.gov/gringlobal/taxon/taxonomydetail?id=415887. Accessed 4 December 2024. of which it is the type species.Ortgies, E. (1851). Die Familie der Nymphaeen. Neue Allgemeine Deutsche Garten- Und Blumenzeitung, 7(11), pp. 481–484. It is identified as the sister group to Nymphaea tetragona and Nymphaea leibergii based on nuclear ribosomal DNA, but the relationships based on the analysis of the chloroplast DNA is unclear.
Etymology The specific epithet pygmaea means small or dwarf.Pleioblastus pygmaeus. (n.d.). Missouri Botanical Garden. Retrieved December 4, 2024, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=285354&isprofile=0&A Grammatical Dictionary of Botanical Latin. (n.d.). Missouri Botanical Garden. Retrieved December 4, 2024, from http://www.mobot.org/mobot/latindict/keyDetail.aspx?keyWord=pygmaeus
Ecology Habitat It occurs in lakes, ponds, marshes, and rice fields.
References