The Hoylake trip will be on 10th not the 17th September as originally advertised 

The Hungarian Mullein Verbascum speciosum near Firwood, Formby (SD28030586) has eight in flower and sixty-three just in leaf.  Phil Smith's paper on the original finding of this species is in BSBI News 119 page 56 at
​https://archive.bsbi.org.uk/BSBINews119.pdf

Thale Cress Arabidopsis thaliana is now the commonest pavement plant in Waterloo. Each year it dominates the walls and cracks for just a couple of weeks, the rest of the year it is pretty inconspicuous, though I have seen it in flower for 10 months of the year, March to December. Native to Eurasia and North Africa it has been introduced and naturalised in the Americas, Africa, Australia and New Zealand. It was the first plant to have it’s genome sequenced in 2000, as it is has relatively few base pairs, just around  135 million. The life cycle can be completed in just 6 weeks.
​

In March / April been restricted to the flora of the Waterloo area (but that is what I am studying anyway). Principally the streets and the Rimrose Valley.
There is an interesting article on the flowering times of urban Cambridge by Chris PrestonThe phenology of an urban street flora: a transect study in British and Irish Botany at https://britishandirishbotany.org/index.php/bib/article/view/44

Clustered Clover Trifolium glomeratum is principally a species of dry, light, drought-prone often somewhat acidic sandy or stony soils near the coast, but also also a rare casual inland. The only known site in the North West of England was at Thornbeck Avenue, Hightown reported on by Phil Smith in BSBI News 124 p35 (link here). I found  about a dozen plants at Kenilworth Road, Ainsdale at SD3072712438 (SD31B) on 7/6/18 in mown grassland close to Shore Road. Kenilworth Road is very rich in plants see the account by Phil Smith's and Pat Lockwood in BSBI News 119 p 34 (link here)

A suprising number of species (23) still in flower, so late in the season