Fooled on April 1st

I surveyed much of Cuerden Valley Park on April 1st starting at Kem Mill. We also took along a bag and a litter picker to do some clearing up as well. Searching for the dippers was our first task which turned out to be futile. Chiffchaffs were in abundance with at least 5 singing in this area with two song thrushes and a lone mistle thrush joining in the chorus. A bumble bee crossed our path and as we watched it we then spotted a small white flower which I did not recognise. I took a sample with us to see if anyone back at the Barn could ID it. Other birds seen were greenfinch, jay and several common tits. On the way to the office we called at Town Brow car park to search for moschatel. This had been reported a couple of days previously. I noticed a lot of butterburr here along with 3 more chiffchaff, a jay and a couple of pheasant. The moschatel was just where we had been told it was;

 On our way back to the car park we saw a tree-creeper, grey wagtail, a goldcrest and heard two separate great spotted woodpeckers drumming.
Once at the Barn we took the by now wilting sample to the botanists in the LWT office. After rejecting it as common whitlow grass and other similar species, we decided it was wall whitlow grass. It was time to check out Stag Lodge so off we went. A few mallard and coot were predominant but it was also good to hear and see 3 greenfinch. Two more chiffchaff, goldfinch and a discarded pneumatic drill were the only other notable observations. Our final circuit was the orienteering trail but more park visitors seemed to have made the birds a lot quieter. With 3 more chiffchaff it made our grand total for the day 13 of this species. Another song thrush, a kestrel, two great crested grebe on the lake, and two sand martins brought our survey to a satisfactory close.

I emailed David Earle BSBI recorder for vc 59 about our botanical find. He suggested it would most likely be thale cress. Another check of the living, rather than wilting specimen proved we had been fooled and it was thale cress