Myriophyllum Brasiliensis

[Majorbloodnok]

Hi, all; forum noob here.

Having just installed a small preformed liner pond to replace a duckweed-infested concrete-lined hole I inherited, I'm now on the learning curve trying to understand different aquatic plant species. The idea is to create a wildlife garden that can better support the newts and frogs that were struggling in the old, stagnant water, and to encourage a wider range of pond life at the same time.

Now, from the research I and my family have done, we realise the pond needs something to oxygenate the water, something sticking out for the dragonflies and so on, some water cover and something to give future tadpoles etc. a bit of shelter. As a result, we've got a minature bulrush, a water lily, a water soldier and some myriophyllum brasiliensis - all recommendations from an aquatic plant retailer (not one of the major chains, but he seemed fairly knowledgeable, and I wasn't risking a fortune if he proved a bit useless).

Now, I've been reading further and found all the stuff about myriophyllum aquaticum being banned for sale by UK plant centres, so my conscience is pricking me. I realise what I've bought doesn't have that name, but I was concerned enough to try to track down the details further, and that's the reason for this meandering long post. Firstly, I've found spp. brasiliensis isn't a true botanical species name - just a trade name - but I can't find anywhere on t'interweb that definitively states what the real species is. I have found several very strong hints that it is a red-stemmed cultivar of spp. aquaticum, which is worrying, but I've also found one or two implications that it is a lower impact species instead. Which to believe if no-one will tell me exactly which species it is?

Secondly, if M. brasiliensis is indeed M. aquaticum in disguise, how is it that it is still available for sale at almost every aquatic plant retailer I've visited? One of the articles I found was an American scientific study identifying different myriophyllum species for sale by their genetic profile and concluding that sale under a different name was effectively a loophole to allow continued supply of invasive species. If that's happening in the US, could that be the case in the UK/EU as well?

I know this post is a lot to read through, so thanks if you've got this far. I'd be really grateful, though, if anyone could provide some real concrete info about this stuff. I should point out that I'm not after simple reassurance (i.e. replies that simply say "don't worry, that species is fine"), but rather pointers to further reading. Of course, if any of you are biologists or have first-hand professional knowledge, I'll happily take any crumbs you can throw my way too.

Thanks a lot for reading.

 

[zozo]

Brasiliensis indeed has red stems if grown under sufficient light and it is much smaller than aquaticum..It is also more difficult to grow than aquaticum and definitively doesn't survive a freezing winter. Aquaticum does survive winters, i still have it already for many years in the garden. As far as i experienced in pond shops around, aquaticum was always sold as 30 to 40cm long bundled stems floating in a tub.. Brasiliensis always nursed in emersed form in a pot on soil and much smaller and more fragile.

Since it wont survive the winter you need to start over again and buy a new one each year.. Simply if you get it through the winter it aint brasiliensis. Even in cool summers or if planted to shady it doesn't realy grow that good. Personaly it is not my favorite plant for in the pond especialy not as oxygenator. Tho it is a cute aquariumplant but as for pond i never was realy impressed with the growth of this plant.. You would be better off with plants like Myriophyllum spicatum, Potamogeton sp., Hippuris vulgaris, Ceratophyllum demersum, or Ranunculus aquatilis

As far as that ban story goes, it realy is a storm in a glass of water.. yes it is banned, but it grows as cosmopolite already for centuries.. First recorded report of M. Aquaticum growing in european outdoor of botinical garden ponds date back to the 17th century. Not saying it is blahblahblahblahblahblahblahs they banned it, but the harm is already done and irreversible. And indeed i believe there yet isn't a law against a plant sp. misidentification. And it happens a lot that plants are sold with wrong name tags.

 

[zozo]

https://www.flowgrow.de/db/aquaticplants/myriophyllum-cf-aquaticum-red-stem


That what's the cf stands for in the name.

In biological naming conventions, cf. is commonly placed between the genus name name and the species name to describe a specimen that is difficult to identify because of practical difficulties, such as the specimen being poorly preserved. For example, "Barbus cf. holotaenia" implies that the specimen is believed to be Barbus holotaenia but the actual identification cannot be certain

 

[Majorbloodnok]

Thanks a lot, Marcel; that's really helpful. What you say makes lots of sense, as well as tying in with a number of the things I've found out myself, and the information in the link you gave me is the clearest description I've read yet.

The pond that I've put in is pretty small - only about 4ft wide by about 5ft long - so I'm not too worried if something doesn't grow at a serious rate. However, whilst I may or may not keep the brasiliensis, I've ordered some callitriche stagnalis since it's apparently a big favourite for newts and is a native plant anyway. From what you say, it's probably sensible if I grow both side by side, and then if the myriophyllum survives the winter then I can take out the whole pot and dispose of properly.

Thanks for your help

 

[zozo]

You're welcome.. I hope you do not get disappointed with the M. whatever brasiliensis.. Myriophyllum in general likes rather eutrophic waters or very rich soils.. i keep my outdoor waters relatively lean and most plants on inert substrates, never had a Miriophyllum grow very good like that. Last year i planted a bit off Red stem and took that basket indoor over the winter and back outside this spring. It still is emersed in the basket and this is all that grew back alll summer long. It's all over described as an easy plant, in my experience it is quite hungry and it needs a lot to be easy. There are many plants much easier with much less.

So what is described in above link mainly contradicts my personal experience.. But who knows maybe i got a different red stem sold as brasiliensis.. Tho it didn't show a lot of red stem this year, it's more pink tip than red stem..

 

[mort]

I have aquaticum and have done for many years. Even though it's technically an invasive species, as zozo mentions, the damage is already done. The responsible thing to do is make sure it doesn't go anywhere else and for this it means burning or killing it off if you need to get rid of it.
The the ban is a bit like shutting the gate after the horse has bolted and there are other species more recently banned here that wouldnt be invasive in our current climate but have been controlled because they would in other parts of Europe (however the ban takes some time to be fully enforceable and there is lots of time after the announcement for stock to be sold).

 

[Majorbloodnok]

I agree and understand about the damage already having been done. However, I can also understand the difficulties of any clean-up or even damage limitation if new introductions are being allowed unhindered. As a result, whilst I don't see the ban as a panacea, I agree with its principles and intend to abide by both its details and its spirit. The information Marcel has pointed me to has really helped clarify, allowing me to make an informed choice, and the more general point that Mort makes about responsible disposal is something I intended to do anyway, but is still well worth stating clearly as has been done here.

Thanks, both