Chinese Medicinal Plants, Herbal Drugs and Substitutes: An Identification Guide by Christine Leon and Lin Yu-Lin. Richmond, England: Kew Publishing; 2017. Hardcover, 850 pages. ISBN: 978-1-84246 387-1. $180.00.

This book is the result of a 20-year multidisciplinary project between the United Kingdom and China that documented the botanical identity, quality, and nomenclature of Chinese medicinal plants in commercial trade. With its compilation of information and images in this book, the joint collaboration among botanists and other scientists at the Royal Botanic Gardens, Kew (RBG Kew) and the Institute of Medicinal Plant Development (IMPLAD) in Beijing has created a publication of impressive, unusual, and unsurpassed scope and depth. From 1998 to 2014, members of the collaborating teams conducted 14 joint field expeditions in 15 geographical areas of China, encompassing parts of 21 provinces and autonomous regions.

Following Mao Zedong’s rapprochement with the West in the early 1970s, traditional Chinese medicine (TCM) emerged as an international model in the global development of traditional medicine systems in public health care. Notably, second to acupuncture, the most commonly used modality in TCM is the plant-based Chinese materia medica. As noted in the introduction of this massive tome:

Ingredient accuracy and quality are central to the safety and efficacy of any medical system and Chinese herbal drug ingredients are no exception. Increasing concern, however, about the lack of rigorous quality control systems, especially in international markets, to prevent the use of unofficial substitutes and adulterants has become urgent. Confidence in the identity of these ingredients underpins many aspects of their supply.

Given that substitution and adulteration of medicinal plant materials appear to be prevalent in the global supply chain for botanical raw materials, extracts, and essential oils, there is a growing need for accurate and authoritative resources (such as the publications of the ABC-AHP-NCNPR Botanical Adulterants Prevention Program) that enable industry members, analytical and research scientists, and other stakeholders in the global medicinal plant industry and practitioner communities to determine authentic botanical ingredients.

The book covers macroscopic identification techniques for 226 Chinese herbal drugs (in both crude and processed forms) and morphological identification characteristics of their source plants. This represents about half of the official herbal drugs listed in the current (2015) edition of the Pharmacopoeia of the People’s Republic of China (PPRC).

The book features the following:

• Reference specimens made from fresh plants (verified using herbarium voucher specimens);
• Approximately 3,000 color photos of living plants and drug materials, with annotations about key features;
• Current taxonomy and nomenclature of the included species;
• Comparative identification of official (i.e., listed in the PPRC 2015) and unofficial species of living plants and their herbal drug counterparts in international trade;
• Guidance on robustness of identifications;
• Conservation categories for all species (including a table of CITES-listed species found in the PPRC 2015); and
• Safety summaries.

Information about the official source plants of each herbal drug is organized into color-coded sections based on plant part used:

• Rhizomes, roots, tubers, and bulbs;
• Aerial parts and whole plants;
• Stems and woods;
• Leaves;
• Flowers and flower parts; and
• Fruits, seeds, and other fruit parts.

Within each of the above sections, the herbal drugs are presented in alphabetical order according to their Pinyin names as used in the PPRC. (Pinyin is the official Chinese spelling system used when transliterating Chinese words into the Latin alphabet.) In the case of a plant species for which more than one plant part is used as the source of an official herbal drug in the PPRC, descriptive information may be found in several sections of the book. For example, white mulberry (Morus alba, Moraceae) is the source of four separate herbal drugs: sang zhi (white mulberry twig), sang bai pi (white mulberry root-bark), sang ye (white mulberry leaf), and sang shen (white mulberry fruit). In this case, the same botanical description is repeated four times, and at least three of the accompanying photographs also are repeated. This is not a criticism, merely an observation.

Fortunately, it is easy to find specific ingredients in the well-conceived index, in which accepted scientific plant names are in bold black type, common English and Pinyin names are in regular (non-bold) black type, accepted (official) pharmacopeial names are in bold red type, and other pharmacopeial names are in regular red type. In all index entries, the page number on which the ingredient name first appears is in bold black type. Like all elements of this graphically rich book, the index has been carefully designed with the end user in mind.

Typically, the entries begin with a one- or two-page spread that includes descriptive information about the living source plant(s), beginning with official pharmacopeia species (sometimes more than one for a pharmacopeial ingredient), and, if applicable, unofficial substitutes. A 1.5-inch (3.80-cm) colored banner that corresponds to the color-coded section at the top of each two-page descriptive spread wraps to the margin of the left-hand page and includes the Pinyin name, the Chinese name in Chinese characters, pharmaceutical name, and drug part(s). The right-facing page features “TCM Properties and Use,” and includes the plants’ energetic properties, channels, actions, and indications. It is only in the upper right-hand colored banner of the plant descriptive spread that one finds any information on the herbal drug’s use. No other chemical, pharmacological, or therapeutic/clinical information is included. This book is intended to describe the official source plant(s), unofficial substitutes, and descriptive details of the crude drug.

Following the source plant descriptive material is a one- or two-page spread on the “Drug Morphology” that includes different recognized forms of the crude drug (such as different cuts, slices, or processed drug descriptions), a detailed section on processing, other common names that may be applied in local or regional markets, details on safety, and commentary on unofficial substitutes, counterfeits, or adulterants. This information is often set off in bordered or shaded graphic elements and may include details on “lesser known unofficial substitutes.”

An example is the treatment of the widely used root dan shen, sourced from Salvia miltiorrhiza (Lamiaceae). The four-page layout is divided into a pair of two-page layouts: one that deals with the dried plant and another that describes the herbal drug. The live plant layout includes the botanical description of the official plant as well as two unofficial substitutes: S. bowleyana and S. przewalskii. “TCM Properties and Use,” on the right page for dan shen, includes the plants’ energetic properties (“bitter and cool”), channels (“Heart and Liver”), actions (“invigorates Blood, dispels stasis, cools Blood, tonifies Blood, calms the shen”), and indications (“heart disease, stroke; poor circulation; menstrual conditions; irritability, insomnia, palpitations; sores and abscesses”).

The two-page herbal drug layout for dried dan shen root provides a description of the official drug and the limits of the macroscopic method of identification. For example, the unofficial substitute S. bowleyana “cannot be reliably distinguished from the drug of the Pharmacopoeia species [i.e., S. miltiorrhiza] using macroscopic characters. Laboratory-based authentication methods [e.g., microscopy, chemical and/or genetic testing] are required and for which there is extensive literature (e.g. Kum et al., 2016). [Kum KY, Booker A, Leon C, Garcia JP, Heinrich M. Salvia miltiorrhiza (Danshen); an NMR-metabolomic and HPTLC-based analysis of products’ quality. Planta Med. 2016;82(S 01):S1-S381.]” A half-page section provides information on seven additional unofficial substitutes, all in the genus Salvia; their geographical sources; and distinguishing morphological characteristics.

Arrangement of the individual sections by Pinyin name as the primary header followed by pharmaceutical name aids in recognition of the ingredient, as the ever-changing and inconsistent universe of “accepted botanical names” is a moving target. For example, the accepted scientific name for the ingredient wu jia pi, which is listed in almost all TCM reference works, including the PPRC, under the scientific name Acanthopanax gracilistylus (Araliaceae), is listed instead under the currently accepted botanical name Eleutherococcus nodiflorus (Araliaceae).

The plant description under each entry is detailed and exact, yet readable and free of unnecessary technical jargon. The “Harvesting, Sourcing and Natural Range” section includes details on when the ingredient is harvested, its habitat, and general distribution in China. It also includes insightful details on specialized growing regions, cultivation, agricultural systems, and provenance-related quality. A brief section on “Conservation Status” discusses wild occurrence, endemism in China, and global status.

The text is accompanied by abundant color photography of varying degrees of quality. Most of the photography is by co-author Lin Yu-Lin, with additional contributions from co-author Christine Leon, PhD; RBG Kew staff; and former staff members. The sheer number (about 3,000) and overall excellent quality of the photographs is a feature that sets this book apart from all other TCM titles available in English. The two-page descriptive spread includes photographs of the official pharmacopeial source plant in situ and close-ups of botanical diagnostic details with captioned arrowed overlays pointing to key descriptors. Many entries include images of commercial production (both large-scale and small holder farms), drying or processing, a plant with the whole root attached, and/or the crude drug in a Chinese market. In most cases, images of the living unofficial substitute plants and their visual differences or distinctions are also included. The scope of the descriptive field photography is possible only in the context of a combined team of botanical and crude drug experts traversing remote locations on expeditions over a long time period.

The living plants represent only half of the book’s photographic presentation. The other half details crude drug morphology in various forms (e.g., dried root, transversely sliced root, or longitudinally sliced root), shot on seamless backgrounds. Captioned details, numbered arrows corresponding to diagnostic descriptions in the text, and magnified visuals are extremely valuable aids for macroscopic identification. Photographs of each of these ingredients, their details, and their source plants required scientific vigilance and photographic skills in their creation. During the 16-year period of collaboration and field work from 1998 to 2014 represented in the book, more than 4,500 physical reference specimens of crude drugs were collected along with corresponding cross-referenced herbarium vouchers. These are housed in the Economic Botany Collection at RBG Kew as well as at IMPLAD in Beijing.

Before the publication of this book, one of our favorite recently published go-to books on the identification of TCM herbal drugs was the impressive Chinese Medicinal Identification: An Illustrated Approach (Paradigm Publications, 2014) by Professor Zhongzhen Zhao, PhD, and Hubiao Chen, PhD, of Hong Kong Baptist University. However, as excellent as Zhao and Chen’s book is, with its coverage of 428 commonly used Chinese medicinal herbs and related materials, some of its material is based on the previous edition (2010) of the PPRC, and it does not include the living source plants from which the dried herbal drugs are derived. 

Chinese Medicinal Plants, Herbal Drugs and Substitutes: An Identification Guide was chosen by the American Botanical Council (ABC) as the recipient of the 2017 James A. Duke Excellence in Botanical Literature Award in the reference/technical category. Like Jim Duke’s own contributions to the field of botanical research (in all its meanings), this book is an outstanding original offering born of fieldwork that combines exacting observation with a passion for perfection. This book is an extraordinary original contribution to the current knowledge of medicinal plants. 

—Steven Foster
Author, Photographer
Eureka Springs, Arkansas

—Mark Blumenthal
Founder and Executive Director, ABC
Austin, Texas