Herbs used in traditional Chinese medicine (TCM) have diverse cultural/historical backgrounds and are described based on complex nomenclature systems. Using the family Aristolochiaceae as an example, at least three categories of nomenclature could be identified: (1) one-to-one (one plant part from one species): the herb guan mutong refers to the root of Aristolochia manshuriensis; (2) multiple-to-one (multiple plant parts from the same species serve as different herbs): three herbs, madouling, qingmuxiang and tianxianteng, derived respectively from the fruit, root and stem of Aristolochia debilis; and (3) one-to-multiple (one herb refers to multiple species): the herb fangji refers to the root of either Aristolochia fangchi, Stephania tetrandra or Cocculus trilobus; in this case, the first belongs to a different family (Aristolochiaceae) than the latter two (Menispermaceae), and only the first contains aristolochic acid (AA), as demonstrated by independent analytical data provided in this article. Further, mutong (Akebia quinata) is allowed in TCM herbal medicine practice to be substituted with either guan mutong (Aristolochia manshuriensis) or chuan mutong (Clematis armandii); and mu fangji (Cocculus trilobus) by guang fanchi (Aristolochia fangchi) or hanzhong fangji (Aristolochia heterophylla), thereby increasing the risk of exposing renotoxic AA-containing Aristolochia species to patients. To avoid these and other confusions, we wish to emphasize the importance of a pharmaceutical name, which defines the species name, the plant part, and sometimes the special process performed on the herb, including cultivating conditions. The pharmaceutical name as referred to in this article is defined, and is limited to those botanicals that are intended to be used as drug. It is hoped that by following the pharmaceutical name, toxic herbs can be effectively identified and substitution or adulteration avoided.