Mike Robinson photographed a couple of uncommon Bexley plants at Upper College Farm on May 26th.
Crosswort is in the Bedstraw family and at the time of the 1983 Atlas of London flora was mainly to be found on the south-east fringe of the capital and then out into Kent, where it is on the county rare plant register, but is fairly widely distributed. GiGL has no Bexley records of it but Tristan Boulton of LACV showed it to me above the Lesnes Abbey ponds a couple of years ago.
Yellow Vetchling (Lathyrus aphaca), a kind of pea, is nationally scarce. There is a also a small amount of it in Belvedere near the incinerator, and rather more on Braeburn Park and also Crayford Rough, though Bexley Council recently voted to build on a significant proportion of the part of that site within which it occurs.