From its first publication in 1858, The Handbook of the British Flora was the most influential field guide to plants found in the British Isles for a century. Its author, George Bentham, was a noted authority in the identification of plants but had no experience in writing for an amateur audience. Not put off by this shortcoming, perhaps due to there being a gap in the market for such a guide, the enterprising publisher Lovell Augustus Reeve acquired the rights to print the work, which would receive an initial print run of 2,000 copies.

The Handbook was comprehensive, providing much more in-depth information than could possibly be of use to an amateur. It included instructions on how to identify a plant without a visual aid (the first edition had no illustrations), an overview of different taxonomic terms and guidelines on how to make an herbarium. To assist the beginner, Bentham chose to list the English names of plants first, rather than their Latin scientific names. While useful for amateurs, this meant that the book was boycotted by universities, who viewed such a decision with disdain, despite it likely being of much use to students. Indeed, the Royal Botanic Gardens at Kew, seeing the merit of the work, sent copies to aspiring naturalists around the world in the hopes they would be able to use its guidance to prepare and send new specimens to the gardens.

Despite its complexity, the book was a huge success with the general public, and this illustrated second edition (issued in parts) followed in 1863-5. Although black and white, the illustrations were incredibly detailed, and some owners of the book took to colouring them in as they went out plant spotting. By 1878, the illustrations were being sold separately in a companion volume for that purpose, further cementing the work’s lasting popularity.

However, Bentham’s approach to identifying and classifying plants was not without its critics among his peers and the success of the book with the public led to a growing gap between professional botanists and amateurs. The Handbook had earned a practical monopoly on field guides aimed at beginners and Bentham refused to amend his text for subsequent editions. After his death and with its popularity ongoing, editorial duties for the Handbook were taken up by Bentham's friend Sir Joseph Dalton Hooker, leading to it being popularly known as 'Bentham & Hooker'. Hooker made important contributions to the work but had promised not to amend the core of Bentham's text, and by the time of its final edition, the book was severely out of date.