There was a load of Galinsoga sp., which looked paler and less hairy than Shaggy Soldier, so may have been Gallant Soldier, in a car park by shops under the railway arches.
In the river it was great to have shoals of Chubb swimming around ones feet, whilst the biggest fish seen was a large, slow-moving Bream.
Later on I checked out one of the other water courses just south of the Cray and east of Maiden Lane.
Here I found my first 'wild' colony of Parrot's Feather (Myriophyllum aquaticum), seen growing with Fool's Watercress and Water Forget-me-not.
Parrot's Feather is another invasive alien (this time from South America), chucked out of garden ponds (I recognise it because I had some in mine back in the late '70s, before it was more widely recognised as problematic) that, according to NERC, is now established at around 300 sites in the UK.