Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Less-weedy Nuphar lutea subspecies?

My questions are, is there a subspecies of Nuphar lutea that is both less weedy, and are they available for purchase? I would like to add these to my pond but am concerned about losing control.

According to the USDA, “Nuphar lutea is divided into many subspecies. Comparisons of morphological features and interpretations of molecular analysis indicate the name Nuphar lutea should not be used for any North American Nuphar members. The genus Nuphar is now represented by eight distinct species in North America.”

The comonly availably subspecies is Nuphar lutea (L.) Sm. ssp. advena. In general, Nuphar Advena (spatterdock) is considered an invasive species that is hard to control due to its rhlyzomic spread, ability to thrive at depths of 2m or greater, and large (up to 40cm) leaves. Unfortunately, it is only this subspecie that is readily available from online suppliers, with a only a few supplying seeds of some other subspecies.

Three subspecies that grow primarily in the North, where I live, are Nuphar lutea rubrodisca, Nuphar lutea pumila, and Nuphar lutea variegata. Two of these, N. rubrodisca and N. pumila, reside primarily in the NE. I believe that both pumila and rubrodisca may have smaller leaves and may be less invasive; N. rubrodisca is generally considered to be a hybrid between N. microphylla and N. variegata. To my questions:
1. Are any of these considered “less weedy?”
2. Where might you procure plants?
Seeds for some are available at esty or others, these will take at least 2 years before they are capable of being planted in 3’ of water and are most likely not of varified subspecie. I might better collect them off a lake somewhere in NY. I don't know if anyone has experience in this area, and may not get many replies, but thought I might try. Any thoughts?

My advice is not to plant ANY Nuphar of any species, instead plant Nymphaea of vairous species that will grow in the water depth that you want them to colonize. They grow very slowly compared to Nuphar.

You can buy tubers and have flowers the same year you plant them, and they are readily available. Just don't buy the tropical variants, they won't overwinter in your pond.

esshup, thanks for the input. I have Nymphaea Odorata in my pond and wanted to add another native flowering lily-like plant. I realize that Nuphar can be a nuisance and was wondering if one of the Northern species were less so. I take it that you have had bad encounters with Nuphar. It appears that N. variegata is native to parts of Indiana. Have you had problems with it crowding ponds?

I will have the Nymphaea well established before adding Nuphar. The N. variegata and N. robodisca are present in counties near where I live. In the Adirondack lakes I have visited for many years, the Nuphar and Nymphaea species seem to coexist. Depending on the lake, the Nymphaea may be more prevalent with only a few clusters of Nuphar. Some have larger areas of Nuphar and other pond weeds.

I realize that these rhyzomic plants are almost impossible to eradicate once established, so I didn't want to be too sorry later. Thanks again for your inputs. I would love to hear what experience you have had with the Northern strains.

The only Northern Strains I've had direct experience with are N. lutea and Nymphaea odorata. Both grow too fast and are considered to be invasive. I have not had any personal experience with any hybrids that grow slower then their parents, only faster (it's called hybrid vigor).

My fear is that once established, and you find out that they are invasive, it will be a royal pain to eradicate them from the pond or you will have to spend a buttload of $$ trying to eradicate them without also killing anything that you want to keep in the pond.

esshup, thanks for your insight. I too am trying to be cautious. Maybe liquidsquid or one of the other NY/New England pondmeisters have had experience in this area. I'm not rushing into this, just yet. Thanks again.

LS just posted on the forum, I'd send him a private message - I don't know if he will see this thread or not.

From my experience do not plant any of the Nuphar species or varieties especially no if they have seeds that sprout. Viable seeds will allow them to be a nuisance in pond conditions compared to wide spread lake conditions. If you want plants of a similar appearance and are even more attractive and useful go with the hardy hybrid Nymphaea varieties. Their seeds are not fertile and the plants do not produce the rhizome buds that break - dislodge, float and cause fast spread. Hardy hybrid Nymphaea come in 4 size classes: dwarf, small, medium and large. As the variety size increases the depth and spread increases accordingly with Large Spread growing fastest and deepest, Dwarf shallowest and shallowest.

If you want a good summary of various types of water lilies for pond habitats see my articles in the back issue of Pond Boss magazine 2010. If the back issues are sold out contact me by Private Message.

Mar-Apr 2010. WATER LILIES IN PONDS. Part 1. Cody discuses features of hybrid water lilies and four types of look-alike species. Control methods discussed.

Jul-Aug 2010. HYBRID WATER LILIES. Part 2. Cody discusses the types of hybrid water lilies, size groups, leaf and depth spread, planting, dividing and transplanting methods.

See this link for our prior pond forum discussions about types of water lilies:

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=110943#Post110943

Bill, thank you for the reply and the good link with many sub-links. It will take a while to read through these. My general take is not to plant natives that can easily spread, but to plant hybrids. I will also order the 2 back issues of Pond Boss you listed (if available). Thanks again for your insights.

PondBoss is about following established norms and procedures, but it is also about pushing the limit. There were concerns raised about planting any sub-species of Nuphar in a pond due to it’s invasive character. The distribution maps for the Northern sub-species of Nuphar, N. Variegata, N Pumila, and N. Rubrodisca, show that the sub-species are not found or rare except for New England and some of the upper Midwest. Not being a biologist, my take is that these are akin to trout in that they will not establish and thrive except in these areas due to the climate. I looked at 2 sources, BONAP's North American Plant Atlas (NAPA), County Level Species Maps BONAPand the USDA NRCS Plants Database from https://plants.usda.gov/home/ https://plants.usda.gov/home/. I looked at the county data as opposed to the state data. There are minor discrepancies between the 2 data sets but they are in general agreement at to the regions where these plants are observed.

N. Variegata is observed in both the Northeast and the upper Midwest. I have included a table of states, number of counties, and percent of counties where N. Variegata is observed.

Nuphar Variegata Observation by County, USDA Database
state: counties where observed: # of counties in state: percent of co where observed
Idaho 1 99 1.0
Kansas 1 105 1.0
Pennsylvania 1 67 1.5
Iowa 2 99 2.0
Ohio 3 88 3.4
Illinois 4 102 3.9
Nebraska 5 93 5.4
Indiana 6 92 6.5
South Dakota 5 66 7.6
North Dakota 13 53 24.5
Delaware 1 3 33.3
Rhode Island 2 5 40.0
Minnesota 54 87 62.1
Wisconsin 46 72 63.9
New York 48 72 66.7
Michigan 63 83 75.9
New Jersey 16 21 76.2
Vermont 11 14 78.6
Massachusetts 13 14 92.9
Maine 16 16 100.0
Connecticut 8 8 100.0
New Hampshire 10 10 100.0

It appears that it would be a challenge, therefore, to establish N. Variegata in much of SD, NB, KS, IA, IL, IN, OH, southern PA, and even SW MN. Like trout, it appears to establish well in counties with cooler climates or higher elevations, although I have not confirmed the elevation hypothesis with data. As can be seen, N.V is rare in a number of upper Midwest states but is observed further down the Eastern Seaboard.

The observation data for these sub-species suggest that my pond may not be far enough north for them to thrive. According to BONAP's North American Plant Atlas (NAPA), County Level Species Maps, BONAP N.Variegata
Nuphar lutea ssp. variegata is native and not rare in 3 counties that surround me but the USDA Database includes my county as one of the southernmost in Western/Central NY where N. V is observed.

Nuphar pumila (previously microphylla) is a small leafed ssp. native to only ME, northern NY, northern WI and MN counties north of Superior. Among the exceptions is the county where I live, which seems generally too far south. We are in a hilly region with many ponds at over 2000ft in elevation, so this may account for the irregularity. My pond is only at 1050 so it is a good possibility that neither Variegata nor Pumila will thrive. It is like trout, if you aren’t high enough or deep enough, better stock something else.

It will be difficult to get plants of these but seeds may be available from 1 or 2 sources, although in low supply. Finding a pond with these plants and procuring some may still be the best option.

P.S. The table looks good in the editor but doesn't show correctly when posted. Any hints on posting tables?

Thought I would try to include the image of the N. Variegata map from BONAP



Only the counties in bright green have known native occurrences.

Maybe and again maybe not. But try it and let us know how it goes. Look at a USA distribution map from 1990 of Channidae. Now use the same assumption you are using for the Nuphar lutea and look at a distrubution map of Channidae in 2023.

Keep in mind that the occurrence records are very probably from public lakes not shallower private ponds with a small surface to volume/depth ratio. Surface to depth ratio can have a pretty big influence on the amount of spread of aquatic floating leaf plants. Information can be biased. My experience with Nuphar is it initially appeared well behaved and seemed to stay contained with slow spread, however when well established it spread pretty rapidly into the shallow areas 7-8ft deep. As esshup mentions try your plan and keep us advised as to your experience with Nuphar as it grows 6 to 10 years.

esshup and Bill, Thank you both for the warnings and watch outs. Fortunately N. Variegata is native to my part of the country and it has struggled to maintain a foothold at its southern reach, as witnessed by the yellow counties in the map where it is native but is also now rare. If I can procure seeds and get them to grow, then I will keep you all updated... 6 years from now.

One question for both, do you have direct experience with the Northern subspecies?

Thanks again.

I have no experience with the Northern subspecies, all my experience is with them down South. (Texas/Arkansas)

When the plant is producing viable seeds, this significantly increases the rate of spreading.