Source: Korotkova, N. & Raab-Straube, E. von (2017+): Cactaceae. – In: Euro+Med Plantbase - the information resource for Euro-Mediterranean plant diversity.
Opuntia fragilis (Nutt.) Haw., Suppl. Pl. Succ.: 82. 1819
≡Cactus fragilis Nutt., Gen. N. Amer. Pl. 1: 296. 1818
A.Naydenova, T., Vladimirov, V. & Bancheva, S. T. 2019: Contribution to the knowledge of naturalised Opuntia species (Cactaceae) in the Bulgarian flora. – Phytologia Balcanica 25: 39-46
