Named for German-British botanist Johann Jacob Dillenius (1684-1747), who first described the species (Hortus Elthamensis: 398, t. ccxcvi, f. 382. 1732). Ker Gawler: “It flowered in the celebrated garden at Eltham before 1732, and was represented by Dillenius, in his Hortus Elthamensis, but the figure has not been applied by Linnæus to any species.”
Ker Gawler called the species Eltham Indian-Fig in English. Haworth called it Dillenian Opuntia.
Maarten H.J. van der Meer (2022 Sep 14). Opuntia dillenii. Dictionary of Cactus Names. Retrieved from https://www.cactusnames.org/opuntia-dillenii