Sir George participated in three major botanical expeditions (to South Africa, 1927-8, East Africa, 1934-5, and Tibet and Bhutan, 1938) which are illustrated in letters, photographs and diaries.

Correspondence of special interest includes letters from botanical explorers Frank and Jean Kingdon Ward, George and Betty Sherriff and Frank Ludlow (mostly from Burma, Tibet and Bhutan) and from King Gustav of Sweden and Stanley Smith (the latter discussing the possible foundation of a Horticultural Trust).

Sir George was also in regular contact with, amongst others, Sir William Wright-Smith (Regius Keeper of the Royal Botanical Gardens, Edinburgh), (1922-56), Professor Harold Fletcher (Regius Keeper of the RBG, Edinburgh), (1958-70), the 2nd and 3rd Barons Aberconway, Sir Eric Savill (Director of the Gardens, Windsor Great Park) (1959-70), Sir Edward Salisbury (Director, Royal Botanical Gardens, Kew), (1943-56)) and various officials connected with Herbaria, Botanical Gardens, Museums, Universities etc, in many different countries.

Of the numerous different associations and committees Sir George was connected with, his membership of the Ministry of Transport’s Advisory Committee on the Landscape Treatment of Trunk Roads (hereafter known as the Landscape Advisory Committee) from 1956 to 1981 (Chairman 1969-81) is most fully reflected in this collection. There are also substantial references to Sir George’s membership of the Department of the Environment’s Advisory Committee on Forestry and Trees in the Royal Parks (1958-79) and the Windsor Gardens Consultative Committee.

Other points of interest include Sir George’s radio and television scripts, speeches etc, his contributions to the 'Dictionary of Scientific Biography' and his connection with Tropical Herbaria.