‘There are a great many ways of holding on to our sanity amid the vices and follies of the world,’ wrote Ronald Blythe in 2008, ‘though none better than to walk knowledgeably among our native plants.’ To many today, when the age-old connection between people and their indigenous flora is in danger of being extinguished altogether, this pronouncement may seem eccentric; but is rightly endorsed by Leif Bersweden in Where the Wildflowers Grow, which vividly describes the botanical journey through Britain and Ireland he undertook last year.