Water plant id please - marsh pennywort?

Billabong Karen · #1 (**permalink**) 12-09-2011, 12:23 PM

This little plant started to grow unexpectedly together with some other plants donated to me by a friend with a garden pond. I was delighted to see these leaves, and thought it was marsh pennywort. Now however I have been reading on another forum about the dreaded invasive floating pennywort, and how difficult they are to tell apart. Here is a photo (with toad!):

And another:

Any help in identifying this would be very grateful received, as it will decided whether I pull the plant out or not.

Dorts · #2 (**permalink**) 12-09-2011, 12:37 PM

You needn't panic, it's not Floating Pennywort!
It looks like one of the smaller Water-lilies, possibly Fringed Water-lily which is a common garden-pond plant, which has a small yellow flower.
Quite safe to leave until it flowers, then you can decide whether to keep it or not.
Dorts.

Kayleigh · #3 (**permalink**) 12-09-2011, 12:41 PM

It looks like water fringe Nymphoides peltata or frog bit I cant really tell them apart the water fringe has yellow flowers and the frog-bit has white I think..
They are lovely plants the frogs love them so nothing to worry about.

Someone more knowledgeable will be able to give a more positive ID but I know its not pennywort.

Billabong Karen · #4 (**permalink**) 12-09-2011, 12:44 PM

Phew - that's a weight off my mind! Thanks so much Dorts and Kayleigh...

jaelen · #5 (**permalink**) 12-09-2011, 09:11 PM

I've been worrying about the Pennywort as well, because I've ordered some for my pond and I wanted to make sure I had the native variety before I put it out.

I spent about 2 hours last night trying to figure out the differences between the British native and the North American invasive, (and it is confusing, because some sites selling plants just call all of them 'Pennywort' or 'Hydrocotyle'

not helpful!)

What I think, (and if I'm wrong, someone please correct me!) is that the native Hydrocotyle vulgaris is sometimes called 'thick-leaved Pennywort'- it's leaves appear very substantial and almost waxy; completely round without any divisions:

Coppermine Photo Gallery - Hydrocotyle vulgaris [9957]

while the invasive variety from North America, Hydrocotyle ranunculoides has more frilly (for lack of a better word

) leaves, like a geranium... in this photo you can see the split in each leaf that divides it from the stem to the edge...

http://www.torrens.org.uk/NatHist/Aqua/HR/Foliage.jpeg

One site said that the invasive Hydrocotyle ranunculoides has become so bad it's actually being banned in some European countries- people buy it for their aquariums, and then when it gets out of hand they tip it into the nearest lake.
The advice given is don't even put it out with the garden recycling- burn it, or if that's not possible then mulch it... it is an extremely persistent plant, and once it takes hold there's no getting rid of it very easily.

Billabong Karen · #6 (**permalink**) 13-09-2011, 08:07 AM

Lordy, what a nightmare!! The good news for me is that my little plant appears to be fringed water lily (hooray!!!) - but I am certainly not going to buy any pennywort from any sources. The invasive species certainly sounds like a disaster. Jaelen, your idea that you mentioned in your other thread of keeping the pennywort you bought in a bucket until you are completely certain sounds like a very sound idea.

Billabong Karen · #7 (**permalink**) 13-09-2011, 08:09 AM

Quote:

Originally Posted by Kayleigh

It looks like water fringe Nymphoides peltata or frog bit I cant really tell them apart the water fringe has yellow flowers and the frog-bit has white I think..
They are lovely plants the frogs love them so nothing to worry about.

Someone more knowledgeable will be able to give a more positive ID but I know its not pennywort.

As far as I can tell from my identification book Kayleigh, frogbit appears to be a floating plant, while fringed lily is rooted, and in addition the underside of fringed lily leaves are a purpley colour... which means I have unexpectedly gained a fringed lily!