Some "alien" invaders - Do you know where to find some?

Discussion in 'Plant Help' started by ghostsword, 10 Feb 2010.

  1. ghostsword

    ghostsword Member

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    Some time ago a member of the London Fishkeeping Club as mentioned going up the Thames looking for plants or pieces of wood. I thought that it was a weird idea, after all, what sort of plant would we find? The water would either be too cold or too dirty.

    Well, maybe I should definitely take the time to go for a walk on the water side.

    Taken from the Telegraph article:

    Crassula helmsii spreads vigorously, having weak stems that can break into tiny sections, each with the ability to root and grow. These fragments can be transferred to new sites by birds or animals - or people. Its unusual physiology also enables it to grow rapidly for up to 20 hours a day, without a dormant season.

    It forms a dense mat of vegetation that out-competes native waterplants and can cause severe oxygen depletion, threatening wildlife and rare plants such as the starfruit Damasonium alisma. Ironically, New Zealand pygmyweed was introduced as an "oxygenator", but instead has become a strangling monster.

    The second plant in the unholy trinity is a South American native, the parrot-feather (Myriophyllum aquaticum). Closely related to the British water-milfoils, it became naturalised here in about 1970. As with Crassula, it grows rapidly and produces many adventitious roots but it is more likely to be dispersed by discarding or deliberate planting than by chance. It has whorls of attractive ferny leaves that emerge from the water. Now found at more than 100 sites in Britain, it overwinters as a rhizome. It too infests waterways.

    The third and most recently introduced villain is the floating pennywort, Hydrocotyle ranunculoides, which again has a close British relative, marsh pennywort (H. vulgaris). First recorded in 1990, this North American native has already spread to more than 40 sites, mainly in the south of England and Wales, and looks set to become a serious problem.

    http://www.telegraph.co.uk/gardening/47 ... aders.html

    Now, do you where we could find some of these alien invaders? It would be really cool to setup a cold water plant tank.
     
  2. gratts

    gratts Member

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    They're literally everywhere! The first 2 species you mention have totally strangled the small brooks and streams near me. Even during the winter there is such a dense matt of these plants, I dread to think what their growth is like come summer, and can't see how much else can survive! :eek:
     
  3. ghostsword

    ghostsword Member

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    I wonder too how can something else keep up with them. :)

    I will need to check outside London, as I doubt that anything will grow in the Thames, at least inside the M25. Obviously if you know where I can get it in London, I would appreciate it.
     
  4. dw1305

    dw1305 Expert

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    Hi all,
    I'd probably try ponds in municipal parks and gardens rather than the Thames itself. Having said that I've walked along the Brentford reach of the Thames (opposite to Kew gardens) to Kew Bridge, and there are some fairly exotic aliens growing from the bank along that stretch, although I'm not sure you can get at the water very easily.

    Myriophyllum aquaticum is still widely sold as a pond plant in the UK, they have just relabelled it "M.brasiliense" or similar. I have some in my pond in the garden, and it seems to have survived being frozen in ice for a month.
    Any Myriophyllum that has a rosette of bright green emergent leaves (they can grow up to a foot above the water surface and look almost like small fir trees) is M. aquaticum. It will look like this:
    parrot2.jpg .

    I also have plenty of Crassula helmsii, (in this case safely stored in the glasshouse) if you want some? I've never grown it submersed, but it is incredibly tough grown emersed, and I had a stock plant on a rock wool block in a litre ice cream container of water for several years without re-potting or feeding it .

    cheers Darrel
     
  5. ghostsword

    ghostsword Member

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    Hi.. I definitely would like some.. I have a emmersed tank at home and would like to try new things.. :)

    Will send you a PM..
     
  6. ghostsword

    ghostsword Member

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    Crassula Helmsii received. A part was submerged, and after a week the stems started to extend towards the light.
    [​IMG]

    What you see on the piece of wood is lots of assassin snail eggs, my own little "pest".
     
  7. Dave Spencer

    Dave Spencer Member

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    It looks a lot like Hemianthus micranthemoides to me. Considering how much I like and use HM, I`ll have to keep an eye out for this plant on my wanderings.

    Dave.
     
  8. ghostsword

    ghostsword Member

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    It does look like it, I will take a closer shot, as I got it growing emmersed.

    DW1305 said that it grows wild on the fields, so maybe talk to him to see if he can sort you out with some.

    The plant is very nice, and forms a dense mat. I don't know why people bother with HC, if this sort of plant is around.
     
  9. Themuleous

    Themuleous Member

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    FYI - New Zealand pygmyweed Crassula helmsii and Parrots feather Myriophyllum aquaticum will be added to Schedule 9 of the wildlife and Countryside Act 1981 and from 6th April, it will be legal to cause them to spread in the wild. Both are highly invasive, so please be careful :)

    More info - http://www.defra.gov.uk/wildlife-pets/w ... le9%20.pdf

    Sam

    EDIT - also, Crassula can grow on both water and land, so dont be tempted to just thrown it on the compost heap, more than likely it'll grow and take over the garden. It really is one plant that should be avoided.
     
  10. ghostsword

    ghostsword Member

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    From my tanks there is only place they would go, to the fire, they will not survive that. The plant is really pretty and seems to be able to form a nice carpet on the tank, and if it grows as a weed, even better, perfect to suck up excess nutrients from the tank.

    I do not have it on full light, but it doesn't seem to bother the plant one bit.
     
  11. Garuf

    Garuf Member

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    It's grown as a carpet plant in the far east but it's a very untidy carpet as a rule. No where near as capable as HC it really needs massive trimmings to get it dense and tidy looking.
     
  12. ghostsword

    ghostsword Member

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    The main issue is that HC needs more attention thanks this plant seems to need. :)

    Someone new to the hobby that wants to have a carpet on their tank, if they choose HC they will have a task at hand, unless it is grown on a mesh mat.

    HC looks very pretty and very dainty, but there is a price for it.

    The mat that I got looked very much like you get a rollup lawn, so thick and compact, it was just perfect.

    Will trim it when it gets to about 5cm tall, and will try to grow more mats from the timmings, just need to figure out the base I need for it.
     
  13. Garuf

    Garuf Member

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    I wouldn't say that, the exact opposite infact. I've grown C H and it's really very high maintenance for such an ugly carpet that it produces. It's really no where near as good as hc.
    And HC really doesn't need to be grown on a mat, why would that make it easier to manage?! I find Hc to be a pretty low maint plant as far as it goes, hairgrass is worse because it needs to be combed. Carpets as a rule are high maint, that's really the be all and end all with them, they use plants that are often weed like and as such will over grow how you want them.
    All rooted plants grow fine in clay substrate like aquasoil or columbo. No matt should ever be needed for a carpet plant.

    Riccia maybe, moss maybe but for a rooted plant never.
    Riccia and glosso I would say are best for newbs, but even then, Hc is easy with enough flow and co2!
     
  14. ghostsword

    ghostsword Member

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    My issue with HC is keeping it rooted. I find it very hard. I was going to get a mat with some sort of sponge in the middle, with tweezers plant it then let it drop to the bottom of the tank, in time the roots should take hold.
     
  15. Garuf

    Garuf Member

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    Hc is pretty brittle initially and you'll always get one or two floaters, simply push it in deeper with your tongs and give it time. The roots are very shallow on it so it doesn't really make much difference but once it's going it will tie in well.
    If you're not planting it stem by stem cut the pot into small cubes ah-la oliver knott and plant it that way since it's less likely to float out. You will however have bits of rockwool floating about in your substrate.
     
  16. dw1305

    dw1305 Expert

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    Hi all,
    I've always kept the Crassula helmsii stock plant in the glasshouse under carefully controlled conditions and "Ghostworld" had to sign a disclaimer saying he wasn't going to release it outside in any cirsumstances. You do need to be very careful with it as it is brittle and all the little cuttings grow if they end up anywhere moist.

    I'm not in work today, but I'll get a photo thursday of the emersed plants (I had to grow a lot for some project work), under the growlights, it does form a very flat red and green carpet, although I expect it will soon grow up towards the light submerged.

    cheers Darrel
     
  17. ghostsword

    ghostsword Member

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    That is correct. The plant is a pest, and from my tank will only go to the fire, not even to compost. I will not even give it, or sell it to anyone, not worth the risk.
     
  18. Ajm200

    Ajm200 Member

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    Off topic Don't know if this helps with the AS problem. I used to have lots of assassin snail eggs scattered around my 60l tank until my son brought home a tiny BN catfish who loves to rasp at them. Never see any now despite loads of AS in the tank.

    Better than the dwarf chain loaches I got to sort them out who clearly prefer algae wafers.
     

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