Nuphar polysepala
Rocky Mountain pond-lily

Alaska Wildflowers | Yellow

Nuphar polysepala
Rocky Mountain pond-lily

Common Names

Indian pond-lily
nénuphar à sépales nombreux
nénufar à sépales nombreux
Rocky Mountain pond-lily
Rocky Mountain cow-lily
Western yellow pond-lily
Yellow pond-lily

Synonyms

Nuphar lutea ssp. polysepala
Nuphar luteum ssp. polysepalum
Nuphar polysepala var. picta
Nympaea polysepala
Nymphozanthus polysepalus

Subspecies

none

Genus: Nuphar (nénuphar)
Family: Nymphaeaceae (water-lily family)
Order: Nymphaeales
taxonomic heirarchy

Etymology

The genus name “Nuphar” is derived from the Arabic word “nūfar,” which refers to water lilies. The species name “polysepala” comes from the Greek words “poly,” meaning “many,” and “sepalon,” meaning “sepals.” This name references the plant’s characteristic multiple sepals.

The common name “Rocky Mountain pond-lily” refers to the plant’s distribution in the Rocky Mountain region of North America.

The common name “Western yellow pond-lily” describes the plant’s geographical range in the western regions of North America and its distinctive yellow flowers. The term “pond-lily” refers to its aquatic habitat.

Duration – Growth Habit

Perennial – Forb/herb

Identification and Information

Vegetative morphology:

Nuphar polysepala, commonly known as Rocky Mountain pond-lily or western yellow pond-lily, is an aquatic perennial herb that grows from a large, thick rhizome, typically 3-8 cm in diameter. The stems are fleshy, thick, and usually 1-2 meters long, mostly submerged or sometimes emersed. The leaves are primarily floating but can also be emersed or submerged. The leaf stalks (petioles) are terete (circular in cross-section and uniformly thick), appearing alternate from the rhizome, and are 1-2 meters long. The leaf blades are leathery, green, and glabrous both adaxially and abaxially (above and below), widely ovate to cordate (heart-shaped), 10-40 cm long, and 6-30 cm wide (1.2-1.5 times as long as wide).

Reproductive morphology:

The inflorescence is a single flower on long stalks originating from the rhizome. The flowers are 5-10 cm in diameter with 6-12 (most frequently 9) large yellow, petal-like sepals 2.5-6 cm long. The sepals’ interior (adaxial) surface is greenish, while the outer (abaxial) surface is bright yellow and sometimes tinged red at the base*. The true petals are inconspicuous and smaller, located near the stamens inside the calyx (sepals), and they are also yellow with reddish or greenish tinges. The numerous stamens are yellow or reddish-purple with thick anthers. The fruit is green to yellow, oval, leathery, ribbed, berry-like capsules containing numerous 3.5-5 mm seeds in a jelly-like mass.

*In my observations, as noted here and supported by other Flora descriptions, the sepals of Nuphar polysepala are bright yellow on the outside (abaxial surface) and greenish on the inside (adaxial surface). This contradicts the Flora of North America (FNA) description, which states the abaxial surface is greenish, and the adaxial surface is yellow. My description may be incorrect.

Uses

For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.

Nuphar polysepala was a versatile resource for Native American tribes, particularly for food and medicine. The rhizomes were a significant food source, prepared in various ways: cooked fresh by roasting or boiling, dried and ground into flour for bread-making, or powdered and used as a thickening agent for soups and stews. Seeds were also consumed, either dried and ground into meal for baking, roasted as a snack, or sometimes popped like popcorn. Young leaf stalks and flower buds were occasionally eaten as vegetables, though this was less common than root consumption.

Medicinally, the plant had numerous applications. Externally, poultices made from roots were applied to reduce swelling and inflammation and treat sores, wounds, and skin conditions. Internal uses included decoctions to address gastrointestinal issues, heart disease, and rheumatic pain. Some tribes used it as a pain reliever and to reduce fevers, and it was also employed to treat respiratory problems. In women’s health, it was used in some communities to treat menstrual disorders, and a decoction of the plant combined with Devil’s Club was used for an “unspecified woman’s illness.” For a comprehensive look at traditional uses, see the Native American Ethnobotany Database.

Ecological Significance and Potential Modern Benefits

Like other members of the genus Nuphar, Nuphar polysepala plays an important role in aquatic ecosystems. It provides habitat and food for various wildlife, including insects, fish, and birds. The large floating leaves create shade and reduce water temperature, benefiting aquatic life. Additionally, the plant contributes to the stability of water bodies by reducing erosion with its extensive root system.

Recent studies have also indicated that compounds extracted from Nuphar species may have medicinal properties. For instance, research has shown that these plants contain various bioactive compounds, such as alkaloids and flavonoids, which have antimicrobial, anti-inflammatory, and anticancer properties [Wang et al., 2015]. These findings suggest that N. polysepala and its relatives could have potential applications in modern medicine.

Distribution and Habitat

Map data from the Global Biodiversity Information Facility (GBIF), NatureServe Explorer, and Kew

Nuphar polysepala is distributed across western North America, including Alaska, western Canada, and the lower 48 United States, primarily from the Rocky Mountain states westward.

It is an aquatic species living in ponds, lakes, sloughs, and sluggish streams.

Classification

References and Further Reading

Guidebooks

Pratt, V. E. (1989). Field Guide to Alaskan Wildflowers: Commonly Seen Along Highways and Byways (p. 29). Alaskakrafts, inc.

Johnson, D., Kershaw, L., & MacKinnon, A. (2020). Plants of the Western Forest: Alaska to Minnesota Boreal and Aspen Parkland (3rd ed., p. 226). Partners Publishing. ISBN 978-1772130591.

Brandenburg, D. M. 2010. National Wildlife Federation Field Guide to Wildflowers of North America. Sterling Publishing. (p. 356)

Classification and Taxonomy

VASCAN. “Nuphar lutea ssp. polysepala”. Retrieved 7/3/24, from https://data.canadensys.net/vascan/taxon/6714?lang=en

ITIS. “Nuphar lutea ssp. polysepala”. Retrieved 7/3/24, from https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=517578

USDA PLANTS Database. “Nuphar polysepala”. Retrieved 7/3/24, from https://plants.usda.gov/home/plantProfile?symbol=NULUP

Uses

Native American Ethnobotany Database. “Nuphar polysepala”. Retrieved 7/3/24, from http://naeb.brit.org/uses/species/2596/

Wang, H., Kong, F., Wang, S., Wang, X., Wu, Y., Zhang, X., & Shen, Y. (2015). Comparative transcriptome analysis to elucidate the primary metabolic pathways associated with the pharmacological properties of two Nuphar species. Journal of Plant Interactions, 10(1), 303-314. https://doi.org/10.1080/17429145.2015.1096785

Map and Distribution

GBIF. “Nuphar lutea ssp. polysepala”. Retrieved 7/3/24, from https://www.gbif.org/species/6434926

NatureServe Explorer. “Nuphar lutea ssp. polysepala”. Retrieved 7/3/24, from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.155521/Nuphar_lutea_ssp_polysepala

POWO. “Nuphar lutea subsp. polysepala”. Retrieved 7/3/24, from https://powo.science.kew.org/taxon/urn:lsid.org:names:1021676-2

Description and Information

Flora of North America. “Nuphar polysepala”. Retrieved 7/3/24, from http://floranorthamerica.org/Nuphar_polysepala

Hultén, E. (1968). Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants (1st ed.) (pg. 450). Stanford University Press.

E-Flora BC: Electronic Atlas of the Flora of British Columbia. “Nuphar polysepala”. Retrieved 7/3/24, from https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Nuphar%20polysepala&redblue=Both&lifeform=7