George Mervyn Lawson grew up in London where he matriculated from Westminster School and King's College in January 1885. After qualifying as Bachelor of Arts (BA) at the University of Oxford in 1889 he underwent religious training and emigrated to South Africa in 1892 to do missionary work in Griqualand West. Initially he was on the staff of St Cyprian's Church in Kimberley, where he was in charge of four missions. Around 1900 he commenced work in the outlying areas and from 1903 until his death was director of missions for Griqualand West. From 1913 to 1941 he furthermore served as Archdeacon of Kuruman in the Anglican Diocese of Kimberley and Kuruman. During World War I (1914-1918) he was chaplain to the Kalahari Horse during the South West Africa campaign and later volunteered for work in Europe.
Lawson was interested in succulent plants and was encouraged in his collecting activities by Archdeacon F.A. Rogers*. He prepared herbarium specimens and presented plants for identification to Maria Wilman*, director of the McGregor Museum in Kimberley, who passed some of them on to the Bolus Herbarium in Cape Town. The species Ruschia lawsonii (Perdevygie) was named after him by Mrs H.M.L. Bolus*.
Lawson later presented his correspondence during the period 1921-1939 to the Kimberley Public Library. Upon his death he left a collection of 247 original drawings and engravings by French, Dutch, Flemish, English and Italian masters to the same library. In 1991 the collection was transferred to the William Humphreys Art Gallery in Kimberley, where it is known as the Lawson collection.