Updated: Unusual plant found near Liskeard!

Feb 22, 2013 by

Updated: Unusual plant found near Liskeard!

UPDATE 27th February 2013.

Ray has sent me a specimen of the unusual plant as outlined below, but unfortunately it died in the post and was hardly recognisable as a plant from the wet mush it had turned into! Ray also reported that he went back to see if he could get more from the site in the field and they had all gone. This makes me think that the plants had either been affected by frost or a virus, and were already well on the way to dying off. We cannot tell whether they were Cardamine corymbosa or C. hirsuta. Brian and Elizabeth Jackson had wondered if it could be very young C. pratensis (Cuckoo-flower) as the terminal lobes in that species when young can look rather large and angular (young C. pratensis leaves can also resemble Ivy-leaved Bellflower Wahlenbergia hederacea). Elizabeth jackson is Cornwall Plant Gall recorder and has an interest in odd plants, and couldn’t find anything like it in her plant gall, or fasciated plants files.

So a mystery which I don’t think can be solved, but as with instances like this worth noting.

Ian Bennallick


Ray Roberts of Bodmin has sent me another photo of an odd plant which he found near Liskeard – does anyone know what it is?

At first I thought it was the strange growth habit of Hairy Bitter-cress (Cardamine hirsuta) but both Mark Spencer (Senior curator of British and Irish Herbarium) and Fred Rumsey of the Natural History Museum have looked at the photo and think it could be another species. Mark has said that – I am inclined to think that it may be C. corymbosa [New Zealand Bitter-cress  – from New Zealand!] that has been freaked out with weedkiller or some other nasty substance! I’ve shown it to Fred Rumsey and he too thinks that may be more likely. I’d grow it on and see if it reverts to normal behaviour to be certain.” Hopefully Ray can get some to grow on.

Possible Cardamine corymbosa Ray Roberts FEB 2013 copy

The large lobes of the lower leaves made me think of Cardamine corymbosa too, and it looks like something has altered its growth. In the photo I don’t see an flowers, but tight clumps of small purple pinnate leaves. If it is temperature or herbicide affected it may explain the odd look to it. On wikipedia there is a paper on Cardamine corymbosa cited in the US journal ‘Weed Technology’ [I wonder how many people knew it existed!] with quite a lot of info on Cardamine corymbosa and some good photos.

According to the paper Cardamine corymbosa …”has a decumbent habit with wiry, unbranched stems, which creep along the ground.” Looking at Ray’s photo it certainly looks as though they are creeping.

Cardamine corymbosa was first recorded in Cornwall in 2000 when Paul Green (field botanist extraordinaire! who incidentally then moved to St Ive not far from Liskeard) found it in Heligan Gardens Nursery. It has since been recorded in 14 separate sites in Cornwall all in gardens of nurseries. One extra site was at Seaton where in 2005 some plants were found in a flowerpot, growing with another adventive Myosoton aquaticum (in Cornwall at least ), and these must have originated from a garden or nursery. David Fenwick has some photos of the Seaton plant on his APHOTOFLORA website – see Cardamine_corymbosa_Seaton 2005. Interestingly it was recorded every year somewhere in Cornwall from 2000 to 2006 then we have no records (though we cannot say it disappeared as it is more likely that the gardens were not visited) until 2012 when some plants were found in Pine Lodge Gardens near St Blazey.
The nearest site to Liskeard is either St Ive (SX3267) where Paul lived until he moved from Cornwall, and Trago Mills at SX1764.


Map of New Zealand Bittercress (Cardamine corymbosa) In Cornwall on a 2km x 2km scale 2000 to 2012

Map of New Zealand Bittercress (Cardamine corymbosa) In Cornwall on a 2km x 2km scale 2000 to 2012

This spring will be an ideal time for people to start looking for it in nurseries and gardens! With no records sent to either myself or to Colin French as BSBI recorders for East and West Cornwall between 2006 and 2012, makes me think that no one has been looking for it or have passed it off as funny Hairy Bitter-cress Cardamine hirsuta!).

Please send any records to the co-ordinator.


Related Posts


Share This