The Cactaceae is a monograph on plants of the cactus family written by the American botanists Nathaniel Lord Britton and Joseph Nelson Rose and published in multiple volumes between 1919 and 1923.

[1] It was illustrated with drawings and color plates principally by the British botanical artist Mary Emily Eaton as well as with black-and-white photographs.

[1] Britton and Rose defined their genera by the characteristics of the cactus plants' vegetation, flowers, and fruit, as well as by their geographic distribution.

[5] Though it was considered definitive in its own day,[4] the taxonomy of Cactaceae has remained problematic, due in part to difficulties in preserving type specimens of cactus.

The great majority of color plates in the four volumes of The Cactaceae are by Eaton, with a handful by other artists such as Deborah Griscom Passmore, Helen Adelaide Wood, and Kako Morita.

[2] One contemporary reviewer called The Cactaceae "the most sumptuous botanical publication" since William Rickatson Dykes' 1913 book The Genus Iris.