trough invader

[ranunculus]

Absolutely?

My English is not brilliant. You can substitute an appropriate expression for it.
I can imagine the results of my effort if I compare Czech writings
by foreigners.

My friend, your English is wonderful ... 'absolutely' was the perfect word in this situation!

My Czech would be 'absolutely' dreadful ...   

Greetings from a cold, but dry Lancashire.

[mark smyth]

Thanks Great Moravian. I have been to Brno botanic gardens two times. Such a good place. The orchid collection   The Peonies ... the rock garden ...

[Paul T]

Well that definitely looks like it takes the 'Calla Palustris' out of the equation.  Wrong leaf venation as far as I can tell.  Hopefully others can come up with what it is.

The ironical comments above suggested you are certain about the identity of the plant.

No, I have no idea on the plant.  Early on I had suggested Calla palustris could be a possibility, but Mark's pic shows the wrong leaf venation (it has a strong central midrib I think, which Mark's plant doesn't have), so I was just commenting that the closer pics cut my earlier suggestion of Calla palustris out of the possibilities for what it was.  I am just hopeful that someone with more knowledge than I have will come up with an answer for Mark as to what it is.  No irony was intended, if that is how my response read.  Apologies.

[Great Moravian]

Two images of Valeriana montana
http://luirig.altervista.org/cpm/albums/bot-011/valeriana-montana13484.jpg
http://www.biopix.com/photos/valeriana-montana-00015.jpg
Probably not identical but sufficiently similar.
Determination of images of plants without flowers is difficult.

[Diane Clement]

Probably not identical but sufficiently similar.
Determination of images of plants without flowers is difficult.  

Fascinating topic.
The venation of Mark's plant is not as the Valerian.  I'd be interested to know if the plants is still green and above ground, or if it has died back by now?

[Great Moravian]

Leaves are cordate and venation different in Calla palustris
http://www.kvetenacr.cz/detail.asp?IDdetail=213

[Great Moravian]

The veination of Mark's plant is not as the Valerian, as Mark's has parallel veins.

Venation is pedate, secondary reticulate.

In Valeriana it is different.

[Great Moravian]

Mark,
You should plant the offsets in a frost-protected place. So we can continue in the spring.
It might be a subtropical plant.

[mark smyth]

Diane the new photos posted on the 22nd were taken that day.

[Diane Clement]

Diane the new photos posted on the 22nd were taken that day. 

I think that's quite significant as some of the plants suggested on this thread would now be finished and underground.

[Great Moravian]

Mark,
Check whether reduced leaves or scales on stolons are alternate or opposite.

[mark smyth]

New photos taken today. Maggie feel free to delete older images to save save

[Great Moravian]

I had never encountered a similar hardy plant before you posted the query.
Leaves are alternate. So I cannot exclude Araceae because of
certain similarity to tropical Cryptocoryne, but venation is different
in Pinellia. The plant could not get in the trough without you helped it.
No blackbird and no ant are responsible for it.
Check the lists of seeds obtained by you recently and
guess which plant it might be.

[Great Moravian]

By the way, don't forget to plant the offset in a frost-protected place.

[daveyp1970]

what about a Rumex