Euphorbiaceae is the sixth largest family of the Angiosperms. This account of the genera of the Euphorbiaceae is based primarily on the unpublished manuscript of the family housed in the Kew archives, which was to have been included by Dr John Hutchinson in Volume 3 of his "The Genera of Flowering Plants". Although his generic descriptions were largely drawn upon for this account, the classification follows Grady Webster's (1994) system. Five subfamilies are recognised, primarily on a palynological basis. 334 genera are described and keyed out. The volume includes 50 black & white line drawings, and a colour frontispiece of cultivated Euphorbs.