Small ex Britton and Rose, The Cactaceae, Descriptions and Illustrations of Plants of the Cactus Family 4: 257, 1923
Opuntia abjecta occurs in the lower Florida Keys where it grows on bare limestone or where a bit of sand or humus has accumulated. Plants may be up to 6-inches tall and form multi-branched mats. The cladodes are 1- to 3- inches long and thick. While not fragile, the cladodes are not firmly attached to each other. The longest spines may be 1- to 2-inches long. Like O. zebrina and unlike O. pusilla, it has teardrop-shaped leaves. The seeds of O. abjecta are about 4 mm in diameter. Some botanists have accepted O. abjecta as a synonym of O. triacantha. We accept O. abjecta as a taxon independent from O. triacantha (also see Majure et al). The type locality is Big Pine Key, FL. See the original citation. Both diploid and tetrapolid samples of O. abjecta have been reported.