Distribution and Ecology of a New Species of Water-lily, Nymphaea loriana (Nymphaeaceae), in Western Canada


  • Diana Bizecki Robson
  • John H. Wiersema
  • C. Barre Hellquist
  • Thomas Borsch




Lori’s Water-lily, Nymphaea loriana, new species, Manitoba, Saskatchewan, conservation, distribution, ecology, endemic, rare


Nymphaea loriana Wiersema, Hellq. & Borsch (Lori’s Water-lily) is a newly described, Canadian endemic species that has been found in central Manitoba and east-central Saskatchewan. To assess the status of a species, data regarding its distribution, population size, habitat, and search effort are needed. The purpose of this paper is to document these factors for this species. The extent of occurrence of N. loriana is approximately 15 100 km2 but the known area of occupancy is a mere 20 km2. The estimated population size of N. loriana is about 750 individual plants, although more may exist on poorly explored rivers and lakes within the extent of occurrence and possibly in northeastern Ontario. Nymphaea loriana occurs in fresh, stagnant, or slowly moving water in boreal lakes and rivers and is typically associated with N. leibergii (Dwarf Water-lily), Schoenoplectus tabernaemontani (Soft-stemmed Bulrush), Potamogeton natans (Floating-leaved Pondweed) and Nuphar variegata (Variegated Pondlily). Potential threats to the persistence of this species include low water quality resulting from mining, forestry, and agriculture, and changes to water flow because of dam construction and climate change. Monitoring known populations and searching for additional ones may be needed to assess the status of this species.