Some material in this descriptive inventory has appeared in my earlier booklet Native Medicine in the Sudan published in 1970 by the Sudan Research Unit, University of Khartoum. Since then, I have continued adding new items, and authenticating and updating information. I have corroborated much of the data other researchers had already collected, and tried hard to work out the relation between Sudanese practices and those documented in Medieval Arabic medical texts. This, I think, is a necessary step towards identifying some historical origins of the Sudanese practices, many of which are similar if not identical to those in neighbouring countries and the Arab world.

In this inventory, I have deliberately omitted all detailed data on pharmacology, phytochemistry, and toxicology. Interested readers may consult the source books and papers on these subjects. Also a few precautions are in order regarding the nomenclature I have used. There are always problems in transcribing Arabic terms into English no matter how stringent the transcription rules are. There are different languages and dialects in the country; all, including 'Arabic dialects, need their own special rules to help readers pronounce them properly. For these reasons, I have reproduced the vernacular names in a transliterated English and in Arabic. Several plants were entered under their currently accepted taxonomic names and also under their synonyms (former names that are no longer used). Authors are added to the binomial whenever available, and synonyms are underlined. Authors of binomials are omitted in the index of this book. However, authentication of the names of plants mentioned in this inventory needs more in-depth professional study.

Furthermore, local people have described some plants by adding the common 'um' (mother of) and 'abu' (father of) as prefixes. For example, Aristolochia bracteolata has the following names: jalajil, abu-jalajil, abu-jiljil, jiljil, jaljil, and 'irq al-'aqrab (the scorpion root). This plant also illustrates another aspect worthy of note, the common use of onomatopoeic and descriptive names. Jalajil, for example, in local Sudanese Arabic as well as in classical Arabic, is a word that stands for the jingling bells that are tied to the feet of babies or animals. The Sudanese also call the seeds of senna jalajil because of this tinkling effect.

Moreover, many plants are named after the causative agent, and, therefore, we find a number of plants of different species called 'irq al-dabib (snake root) or 'irq al-'aqrab (scorpion root), for example. In view of this liberty in using prefixes and descriptive names, researchers should be duly careful in identifying such plants.

This work has relied on extensive field surveys of traditional practices. It has also drawn extensively on the information that has accumulated in the literature throughout the last two centuries. I have visited many regions in the Sudan since 1966 to interview both healers and laity about their local recipes; all gave me valuable information. I have reviewed most of the literature on traditional medicine, and scanned with particular care most of the early anthropological and ethnographic studies on the different cultural groups in the country. With assistance from experienced taxonomists, I have meticulously checked and compared the vernacular and binomial names reported in the different sources. This has been a difficult job because there is no reference point. The only herbarium the country had, the Wellcome Laboratories herbarium, has been lost. A new herbarium has been started in the Medicinal and Aromatic Plants Institute 'in the National Council for Research, Khartoum; this is the only reference point for checking and authenticating medicinal plants in the country. To perform its functions properly, the Institute has launched several projects to collect, identify, and preserve herbal specimens. Had these projects been fruitful, or their results available, individual endeavours such as this would naturally have taken a different approach. In the meantime, the data in this inventory, and indeed, any data collected similarly, should be welcome additions, but should always be subject to specialized critical examination.

Researchers and institutions may find further information of a much wider nature and appeal in the Natural Products Alert acronymed NAPRALERT. This is a computerized plant information data base maintained in the WHO Collaborating Centre for Research in Traditional Medicine in Michigan, Illinois, USA. This data base is huge and comprehensive, and is particularly helpful in solving certain problems that researchers face in pharmacognosy and traditional medicine. The information in this centre is accessed through the WHO regional offices.

The preparation of medicinal recipes is often a skilled practice that differs from healer to healer. I have omitted the details that individual healers give for preparing recipes. Important as they may appear, I have not found them consistent; there are no uniform methods of weighing and combining the ingredients. Nonetheless, I have included the main principle involved whenever appropriate; these I thought should be of help for future researchers to take the subject further.

I have transcribed the vernacular terms (names of diseases, plants, organic and mineral items) exactly as the healers or the laity pronounce them. To help the Sudanese reader recognise these words easily, I included their Arabic transcript appended to this book.

Some medical terms I have used in this work may appear vague when measured by modern medical rules. For example, liver pain and stomach-ache connote diagnoses different from the ones a modern practitioner would tend to understand. However, this is the terminology the healers and the laity use, and it is part of their system of medicine. I have therefore used modern medical sparingly, and even then, I have used the terms that have general rather than technical applications.

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