Nymphaea × thiona is a species of waterlily native to the US-American states Alabama, Florida, and Georgia. Additionally, it has been introduced to Costa Rica, as well as the US-American states Kentucky, and Nevada. It is a natural hybrid of Nymphaea mexicana and Nymphaea odorata.
Description
Vegetative characteristics Nymphaea × thiona is a perennial herb.U.S. DEPARTMENT OF AGRICULTURE. (n.d.). Nymphaea ×thiona Ward [mexicana × odorata]. USDA Plants Database. Retrieved May 27, 2025, from https://plants.usda.gov/plant-profile/NYTH The rhizomes can be stoloniferous or not stoloniferous.Nymphaea mexicana in Flora of North America @ efloras.org. (n.d.). Retrieved May 27, 2025, from http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500827 It exhibits more vigorous growth than its parent species.Nymphaea mexicana in Global Plants on JSTOR. (n.d.). plants.jstor.org. https://plants.jstor.org/compilation/Nymphaea.mexicana
Generative characteristics The flowers extend above the water surface. The flowers are larger than flowers of Nymphaea mexicana, and more yellow than Nymphaea odorata flowers. Fruits are unknown.
Reproduction It is a sterile hybrid. Fruits have never been observed.Ward, D. B. (1977). Keys to the Flora of Florida -- 4, Nymphaea (Nymphaeaceae). Phytologia, 37(1), 443–448. http://www.biodiversitylibrary.org/openurl?ctx_ver=Z39.88-2004&rft.date=1977&rft.issue=5&rft.spage=445&rft.volume=37&rft_id=http://www.biodiversitylibrary.org/bibliography/12678&rft_val_fmt=info:ofi/fmt:kev:mtx:book&url_ver=z39.88-2004Sutton, D. L. (1993). Water-lilies of Florida. TropicLine, 6(6). https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=d2da0045ae3990527c36c3bcb42157893dde7f11 It can reproduce through stolons.
Taxonomy It was first described by Daniel Bertram Ward in 1977. The type specimen was collected by C. Hoy in drainage canals of marshes in St. Marks National Wildlife Refuge, in Wakulla County, Florida, USA on the 15th of April 1962.Holotype of Nymphaea thiona D. B. Ward [family NYMPHAEACEAE]. (n.d.). JSTOR. Retrieved December 28, 2023, from https://plants.jstor.org/stable/10.5555/al.ap.specimen.gh00038038 It is placed in the subgenus Nymphaea subg. Nymphaea.USDA, 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=415950. Accessed 27 May 2025. Etymology The specific epithet thiona expresses an association to the name Sulphur Waterlily.
Distribution It exists in areas of sympatric occurrence of the two parent species. It is native to the USA (Alabama, Florida, and Georgia). It has been introduced to other American states (Kentucky, and Nevada), Costa Rica, New Zealand,Manaaki Whenua – Landcare Research. (n.d.). Nymphaea ×thiona D.B.Ward. Biota of New Zealand. Retrieved May 27, 2025, from https://biotanz.landcareresearch.co.nz/scientific-names/f6ddf280-7d02-4ed7-9568-9cc30507bbf3 Italy,Nymphaea ×thiona D.B.Ward nothosubsp. thiona. (n.d.). Portale Della Flora D’Italia - Portal to the Flora of Italy. Retrieved May 27, 2025, from https://dryades.units.it/floritaly/index.php?procedure=taxon_page&tipo=all&id=13107 and Sweden.Tyler, T. (2017). Nya och gamla näckrosor i svenska vatten. Botaniska Notiser: utgivna av Lunds botaniska förening (2001-), 150(2), 15-21.Nymphaea x thiona D. B. Ward. (n.d.). Naturhistoriska Riksmuseet. Retrieved May 27, 2025, from https://herbarium.nrm.se/specimens/S-A1849-2
Cultivation It is also known from artificial, horticultural hybridisation.
References