Not just minor wild edible forest products: consumption of pteridophytes in sub-Saharan Africa

BACKGROUND Gathering of wild edible plant resources by people in sub-Saharan Africa is discussed with reference to pteridophytes, which is an ancient plant group. Pteridophytes are crucial to food diversity and security in sub-Saharan Africa, although they are notably neglected as a result of inadequate research and agricultural development. Current research and agricultural development agenda still appear to focus on the popular and commonly used food crops, vegetables and fruits; ignoring minor and underutilized plant species such as pteridophytes which have shown significant potential as sources of macro and micro nutrients required to improve the diet of children and other vulnerable groups in sub-Saharan Africa. Documentation of edible pteridophytes is needed to reveal the importance of this plant group in the region and the associated indigenous knowledge about them; so that this knowledge can be preserved and utilized species used to combat dietary deficiencies as well as improve food security in the region. The aim of this study is to present an overview of food value of pteridophytes in sub-Saharan Africa using available literature and to highlight their potential in addressing dietary deficiencies in impoverished communities in the region. METHODS This study is based on review of the literature published in scientific journals, books, reports from national, regional and international organizations, theses, conference papers and other grey materials obtained from libraries and electronic search of Google Scholar, ISI Web of Science and Scopus. RESULTS A total of 24 taxa belonging to 14 genera and 11 families are used in sub-Saharan Africa as fodder and human food. Pteridium aquilinum (L.) Kuhn is the most common edible pteridophyte in sub-Saharan Africa, used as human food in Angola, Cameroon, DRC, Gabon, Madagascar, Nigeria and South Africa, followed by Ophioglossum reticulatum L. (South Africa, Swaziland and Zanzibar), Ceratopteris thalictroides (L.) Brongn. (Madagascar and Swaziland), Diplazium sammatii (Kuhn) C.Chr. (DRC and Nigeria), Nephrolepis biserrata Sw. (DRC and Nigeria) and Ophioglossum polyphyllum A. Braun (Namibia and South Africa). The majority of edible pteridophytes are eaten as vegetables or potherbs (66.7%), with some eaten raw or as salad or edible rhizomes (12.5% each). Literature search revealed that some of the documented pteridophytes have high macro and micro nutrient content comparable to recommended FAO/WHO daily nutrient intake from conventional food crops and vegetables. CONCLUSION This study demonstrated the capability of literature research to reveal traditional knowledge on edible pteridophytes in sub-Saharan Africa from dispersed primary ethnobotanical data. Findings from this study suggest that edible pteridophytes could make an important contribution to provision of macro and micro nutrients to the sub-Saharan African population. This study also provided evidence of the importance of pteridophytes as food sources, and can therefore, used to enhance food security in the region by complementing the major food crops, vegetables and fruits.