Griffiths, Monatsschrift fur Kakteenkunde 23: 133, 1913
Herbarium NOTE: the herbarium submission is notable because it contains two different plant species. Only the lower cladodes (smaller) conform to the the description of O. nemoralis. The upper cladodes (larger) are another Opuntia species.
Details (Joe Shaw and Barry Snow)
Opuntia nemoralis has been observed in saline prairies, sandhills, and shale outcrops in AR, LA, and TX. Perhaps it occurs in adjacent states. Plants observed north of Lake Ouachita in AR were glaucous/pruinose, especially in winter, whereas plants near Longview, TX had purple areoles. O. nemoralis is uncommonly encountered. It forms low clumps 2- to 4-inches tall and up to 2(3)-ft across. O. nemoralis has been erroneously conflated with O. humifusa. However, it is different from O. humifusa although it is a member of that clade. See the original description. O. nemoralis is tetraploid.