Plant Resources of Tropical Africa

PROTA retired in 2013 while facing large operational costs after its funding expired. At the point of its retirement, about 50% of PROTA's encyclopedia series was complete. During its operation, PROTA received funds from the European Union's Directorate-General for International Partnerships,[8] Netherlands Ministry of Foreign Affairs, Netherlands Ministry of Agriculture, Netherlands Organization for Scientific Research, Wageningen University,[9] COFRA Foundation,[10] International Tropical Timber Organization,[11] and the Bill & Melinda Gates Foundation. Since the program's retirement there have been ongoing efforts to fundraise and preserve PROTA's various publications and online database.[12]

As of 2022, the PROTA database Prota4U is still online in an archive-like capacity at Wageningen University with articles written in English and French. Information in the PROTA database can also be accessed at the website Pl@ntUse–though in a different format. As of 2019, Prota4U had about 1,500 daily visitors and 500,000 unique visitors each year.[12] All of the PROTA's encyclopedia volumes have been digitized and are available for free as Open access publications from the Wageningen University library. It is uncertain how much of the PROTA Recommends Series has been digitized.

The PROTA Handbook Series is a large illustrated encyclopedia series of utility plant species found in Tropical Africa. PROTA's retirement in 2013 made it unfeasible to complete the encyclopedia series, therefore only 9 volumes were ever published. In 2002, the series was projected to contain 16 volumes with entires for 7,000-8000 species. It was estimated that the series would include 2,500 botanical line drawings, and 2,500 species distribution maps in about 11,000 pages.[15] The existing PROTA encyclopedia volumes been described metaphorically in the Kew Bulletin as a treasure trove of information.[16] The Food and Agriculture Organization and Biodiversity International described PROTA 2: Vegetables as a detailed collection of ethnobotanical knowledge.[17] Some PROTA encyclopedias have received more than 376 citations.[18] PROTA Encyclopedia editors included individuals such as G.J. Grubben, who had led projects commissioned by the United Nations International Board for Plant Genetic Resources; and Ameenah Gurib-Fakim, a biodiversity scientist who later became the President of Mauritius.[19] Though organized by species according to conventional botanical nomenclature, PROTA encyclopedias also include vernacular names in major African languages such as Swahili where information was available.[13] PROTA continued to distribute its encyclopedias after the organization's retirement. As of 2019, than 30,000 PROTA encyclopedias had been printed in English and French and were distributed widely with the help of the Technical Centre for Agricultural and Rural Cooperation (CTA) and the now-retired Agromisa Foundation. Several PROTA encyclopedias are also available at the International Union for Conservation of Nature (IUCN) Headquarters' Library in Switzerland.[20]

Species articles in the PROTA encyclopedia series were written by hundreds of authors from around the world and in Africa, and cover a range of information including:[21][13][22]

• plant uses
• geographic distribution by African country
• cultivation information
• wild-collection data
• production and international trade data
• chemical properties
• botanical characteristics
• ecological information
• conservation status

Currently, all published PROTA encyclopedias volumes have been digitized and are available as Open access publications from the Wageningen University library.[23] Several encyclopedias in the series were planned but not started at the time of PROTA's retirement in 2013.

• According to Google Scholar PROTA 2: Vegetables has been widely cited, receiving more than 367 citations as of October, 2022.[18]
• Nigerian ethnobotanists reported in 2004 that PROTA 2: Vegetables included contributions from over 100 authors and detailed cultivation practices for 280 indigenous vegetables.[22]
• A 2004 report from the University Of Ile-Ife in Nigeria referenced PROTA 2: Vegetables to emphasize the importance of indigenous vegetables such as Solanum macrocarpon and Telfairia occidentalis in providing employment opportunities in informal economies and in incorporating indigenous vegetables into plant breeding programs.[22]
• A 2004 book review in the Kew Bulletin regarded PROTA 2: Vegetables as being well cited, with over 1500 references.[24]
• A 2004 book review in the Nordic Journal of Botany commented that PROTA 2: Vegetables "should be found on the bookshelves of every institution dealing with tropical botany, nutrition, health, and agriculture" [25]
• A 2004 book review from the Food and Agriculture Organization (FAO) and Biodiversity International said that PROTA 2: Vegetables brought needed addition to literature about vegetable resources in Africa, and that many of the vegetables described in the volume are unique to Africa. The book review also commented that PROTA2: Vegetables was particular useful for its detailed collection of ethnobotanical knowledge about both domesticated and wild-harvested vegetables in Africa.[17]

• A 2006 book review of PROTA 3: Dyes and tannins published in Economic Botany noted that "the information contained in this volume highlights a number of lesser known species, and is a rich source of interesting information for anyone working at the interface of ethnobotany and domestication, and as such is a must have."[21]
• About 64% of the 24 authors of PROTA 3: Dyes and tannins were from Africa.[9]

• A 2014 book review of PROTA 11(2): Medicinal Plants noted that about 30% of the contributions were written by African ethnobotanists.