This poorly documented species is apparently very localized and/or uncommon in its range, and is known from only a few specimens; the area where it occurs is not at all well explored botanically. Isertia wilhelminensis can be recognized by its robust habit, its rather large stipules (ca 20 mm long) that are so deeply divided they almost appear to be free, its cymose terminal inflorescences, its rather large red to yellow corollas, and its drupaceous fruits with numerous seeds inside each pyrene.