The importance of botany, agriculture and gardening is apparent throughout the collection. The Fagel Collection acquired at the start of the 19th century contains many notable and spectacular works including L. Fuchs, De Historia Stirpium Commentarii, Basel, 1542, and J. Commelin, Horti Medici Amstelsdamensis Rariorum Plantarum Descriptio, Amsterdam, 1697-1701.
The works in the Library cover botanical investigation of all parts of the world. Many of the early works reflect the excitement of discovery of new plants in the Americas, Africa, and Australasia. The gardening books show the transfer of the newly discovered plants into domestic gardens. The development of agricultural science is well recorded with a particularly good range of works on Ireland and Great Britain.
The Manuscripts & Archives collection includes correspondence of two Professors of Botany, William Henry Harvey and Henry Horatio Dixon.