Image: C. Ferguson-Smyth
One footnote I'd add to Ken's piece is an observation about Campanula rotundifolia, known commonly as Harebell in England and Scottish Bluebell in Scotland. It is one of the plants that many English botanists have long thought of as fairly common [in a nice way!] and widespread, even in the lowlands, but which the England Red List analysis reveals as Near Threatened.
Sorry to give you bad news about a much-loved wild flower, but maybe the ERL will act as the wake-up call many feel is needed for greater efforts to conserve all our wild plants across this (still) United Kingdom.