It became one of the genera which he was best known, and many species of which now bear his name.[80][24] Epimedium and the related woodland perennial Vancouveria (Berberidaceae) would be the subject of his first monograph (1938)[81] and were genera to which he would return at the end of his life.[82] At the time the taxonomy of this genus was very confused, and with the help of the Cambridge Herbarium he obtained specimens from all over Europe to produce a comprehensive monograph.[11] The work was so thorough that it was mistakenly considered a doctoral thesis by other botanists.