
Nuphar polysepala
Nuphar polysepala
Safety & Hazards
None known
Cultivation Details
A water plant requiring a rich soil and a sunny position[1, 2]. It is best grown in still water up to 75cm deep but it also tolerates slow moving water[3]. Succeeds in light shade[3]. Plants are hardy to about -20°c[4].
Propagation
Seed - sow as soon as it is ripe in a greenhouse in pots submerged under 25mm of water. Prick out into individual pots as soon as the first true leaf appears and grow them on in water in a greenhouse for at least two years before planting them out in late spring. The seed is collected by wrapping the developing seed head in a muslin bag to avoid the seed being lost. Harvest it 10 days after it sinks below the soil surface or as soon as it reappears[3]. Division in May. Each portion must have at least one eye. Submerge in pots in shallow water until established[2]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Nuphar+polysepala>
Pollinators
Flies, Beetles
References
- [1]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [2]Complete Guide to Water Plants. — Muhlberg. H. · E. P. Publishing Ltd. · 1982 · ISBN 0-7158-0789-7 ↩︎Deals with a wide range of plants for temperate areas (and indoor aquaria) with quite a lot of information on cultivation techniques.
- [3]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [4]Perennials. Volumes 1 and 2. — Phillips. R. & Rix. M. · Pan Books · 1991 · ISBN 0-330-30936-9 ↩︎Photographs of over 3,000 species and cultivars of ornamental plants together with brief cultivation notes, details of habitat etc.
- [5]Vascular Plants of the Pacific Northwest. — Hitchcock. C. L. · University of Washington Press · 1955 · ISBN - ↩︎A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader.
- [6]A Field Guide to Rocky Mountain Wildflowers — Craighead. J., Craighead. F. and Davis. R. · The Riverside Press · 1963 · ISBN 63-7093 ↩︎Excellent little pocket guide to the area, covering 590 species and often giving details of their uses.
- [7]Sturtevant's Edible Plants of the World. — Hedrick. U. P. · Dover Publications · 1972 · ISBN 0-486-20459-6 ↩︎Lots of entries, quite a lot of information in most entries and references.
- [8]Food Plants of the N. American Indians. — Yanovsky. E. · U.S. Depf of Agriculture. · ISBN - ↩︎A comprehensive but very terse guide. Not for the casual reader.
- [9]Edible Native Plants of the Rocky Mountains. — Harrington. H. D. · University of New Mexico Press · 1967 · ISBN 0-8623-0343-9 ↩︎A superb book. Very readable, it gives the results of the authors experiments with native edible plants.
- [10]Common Edible and Useful Plants of the West. — Sweet. M. · Naturegraph Co. · 1962 · ISBN 0-911010-54-8 ↩︎Useful wild plants in Western N. America. A pocket guide.
- [11]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
- [12]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
- [13]Edible Wild Fruits and Nuts of Canada. — Turner. N. J. and Szczawinski. A. · National Museum of Natural Sciences · 1978 · ISBN - ↩︎A very readable guide to some wild foods of Canada.
- [14]Discovering Wild Plants - Alaska, W. Canada and the Northwest. — Schofield. J. J. · Alaska Northwest Books; Alaska · 2003 · ISBN 0882403699 ↩︎A nice guide to some useful plants in that area.
- [15]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.