The latest revision of the Red Data Book for wild flowers will list some 340 species which it characterists as ‘rare’, ‘vulnerable’ or ‘endangered’ – roughly one quarter of the British flora. That is not in itself an indication that anything is wrong. There are perfectly natural reasons why some species will always be rare: plants at the edge of their natural range; plants with highly specialised lives or which live in unusual habitats; ‘relict’ species left stranded on cliffs or mountain tops by changing conditions and the shift of time.
