Discussion in 'Aqua Essentials' started by Aqua Essentials, 14 May 2018.
Ha, ha, yes alto, you were too slow.
Thanks. I only quickly "googled" around. Point is they're supposed to be rooted, so not much of a floater..
There are some good Trapa natans "floating mat" photos in this article (eastern Canada)
Lol, I thought some-one would beat me to it, as it took ages to type that post, kept getting interupted.
I read the quote in confusion then kept looking for good photos of a "field" of E dulcis
Well, at least I know someone is paying attention
This plant has been available to purchase in the UK from at least the end of the Great War. I have a book written by the Rev Bateman who notes that it is a great favorite with some aquarium-keepers. The plant can often be bought in London for a moderate sum. His books predate the inclusion of a print or publication date. I st Edition is 1890 or 1918, depending of sources. My copy is the 7th Edition which only really differs by the inclusion of descriptions and illustrations of fish not generally imported into England at the time of former editions. Trapa natans has not managed to 'jump over the garden wall' and become naturalized in about 100yrs. By contrast the rare, in Bateman's time, Villarsia nymphaeoides is now fairly wide spread, I assume by the dumping of surplus pond plants by gardeners. Both plants are readily available from garden centres.
By the by, Bateman illustration of T natans shows a central stem with a rosette of leaves at the top and roots at the bottom.
Darrel's point about poor UK summers as opposed to cold winters is a good one.
Not sure about it at all now, I had a look at a couple more references and about 5,000 years ago it seems to have been native all the way north to <"Finland">. This is one from <"Yorkshire">
We have Nymphoides peltata in one of the lakes at work, and it is very good grower. I think it is also an invasive in New Zealand, Ireland etc.
I've had Trapa natans as a leaf rosette, and it has never looked happy. I wonder what would happen grown from seed.
But the Holocene was a warm period and Trapa natans has not naturalized in the UK. Leastwise I have never found it not even in the Kent Marshes where Azolla can be the Dominant plant community in both lead drains and sewers, cutting the light levels so low that obligate aquatic die.
We have Nymphoides peltata as it is now called in our garden pond. Came as a plant sample I found in one of the Kent drains. Grows fast but likes to have some of its roots in the pond substrate. Its a green bin a year plant.
Is Ttrapa natans a true floating plant or is it more like a water lily, a rooted plant with floating leaves.
Here you see a picture showing it developing stages.. From nut to adult plant.
I do not know how it does in the tropics, but in temporate regions its an anual plant, completely dies off in the fall and needs to seed itself again. The seeds are frost sensitive also, if they freeze they lose fertility.
A water lily grows from a tuber or a bulb as it is commonly called. That is an evergreen in the tropics and in temporate regions it comes back from the same tuber that is winter hardy. Exept the tropical lilies..
Many thanks, I thought it was not a true floating plant, like say duckweed. Small wonder it struggles to grow as just a top rosette of leaves.
Very good set of pictures that clearly shows it growth stages. Interesting about frost sensitivity of its seeds, explains a lot. Many tropical plants survive being frosted by growing back from root stock and can thus survive in temperate zones to become invasive. Frost sensitivity must restrict its range in Europe.
On a different note have you grown greater duckweed, Spirodela polyrhiza.
Conserning T. Natans it is a mystery why it dissapeared from europe. It grew here abundatly at times with colder winters than today. It's seed should sink deep enough for the frost not to reach it, than it can germinate in the spring. And since it a sun worshiper and the summers got hoter means more sun less clouds.. It all doesn't realy add up why it is gone. I actualy never tried to grow it from seed, would be a nice experiment for next summer, i see if i can get some.
No i never did, i stopped at Lemna minor and still strugling with trying to get rid of it. That's enough duckweed for me.. Never again if i ever get it all out.
The two smaller duckweeds are a pain. Thankfully never had L minor, L gibba was bad enough. Tried without any luck at growing L polrhiza/Spirodela polyrhiza. Found L trisulca just faded away.
I have grown both of these and they have different requirements, Spirodela polyrhiza likes high conductivity (even for a Duckweed) and hard water. The last place I saw it, in any amount, was on the <"Steart Marshes"> in 2016, it was in the freshwater marsh, but the water was about 2000 microS.
Lemna trisulca prefers hard water, but the main thing is that it likes fairly nutrient deficient conditions. It has persisted in my tanks for ~10 years, but always in tiny amounts.
Thanks Darrel, I tried to grow Greater Duckweed after collecting some from a large pond in the R. Severn catchment, many many years ago. Small wonder I failed. Petri Dish & Desk Lamp with lean nutrients. Still Prof was amused. Nearly drowned myself in Avignon this summer trying to get some more out of the Rhone, high mineral content judging from its blue colour.. Failed, stick was not long enough.
Ivy leaved duckweed was always in Black Country canals, if you cycled long enough. In those days the wisdom was never change your aquarium water, old water was good. Small wonder I failed. Live and learn and stay alive. Great site.
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