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. O. abjecta is diploid.