Brookes was born on 5th September 1868.
On 14th February 1896 he was employed by the Department of Agriculture and Stock. He was an overseer at Kamerunga State Nursery in 1900 and in May 1901 was appointed manager of Biggenden Slate Farm. In October 1904 he was transferred to the Queensland Agricultural College at Gatton working as farm foreman. Later records in 1919 show him as an Instructor in Agriculture stationed at Rockhampton. Queensland Herbarium records indicate that Brookes collected between 1917 and 1929 at Alton Downs and in the Rockhampton district. In April 1919 he published a detailed 'Report on Investigations in Regard to the Spread of Prickly Pear by the Scrub-Turkey'.
Source: Pers.Comm. Helen Cole (1988) and Brookes, G.B. (1919).
Published in Port Curtis District Flora and Early Botanists by G.N.
Batianoff and H.A. Dillewaard (1988), Botany Branch,