The growing interest in the use of wild food plant resources nowadays stems from efforts to find alternatives to the industrialization and globalization of agriculture and to provide food security in times of agricultural crisis. In the not so distant past many wild plants, instead of being eliminated from agricultural systems, constituted valuable supplementary sources of nutrition [1]. Within the last two decades, detailed ethnobotanical studies have been carried out in European countries to preserve the disappearing traditions of wild food plant use. Such studies were performed for instance on the Iberian Peninsula (e.g. [2-8]), in Italy [9-13], Greece [13,14], Turkey [15,16], Bosnia and Herzegovina [17], Albania [18] and Austria [19]. The phenomenon of foraging in Europe has been, however, studied from different perspectives for centuries. It was present in economic plant encyclopaedias [20][21][22][23] and later appeared as the subject of ethnographic studies. A separate branch of study concerns wild food plants as a means of alleviating food shortages during times of crop failures and wars [24,25]. Countries where ethnobotanical studies are most intensive now are usually places where little ethnobotanically oriented research has been done before. In contrast, there are a few European countries in which research on the ethnobotany of rural populations started at the end of the 19th century. Here we shall first of all mention two of them. One is Poland, where local ethnographic monographs, Józef Rostafiński's study of 1883, and the "Polish ethnographic atlas" all contributed to a large body of data concerning the use of wild food plants [26][27][28][29]. The other country is Estonia, where a similarly large number of ethnographic elaborations and queries is availableand it has been recently synthesized [30]. Łuczaj and Szymański [26] pointed out that the crosscultural and geographical analysis of the patterns of plant use in Europe is hindered by the fact that most publications were written in national languages, mainly in small ethnographic journals and monographs. Thus English-language critical reviews in widely available journals can constitute "building blocks" for further international analyses. The studies from Poland show a gradual disappearance of traditions of wild food gathering, since the 19th century or even earlier [26][27][28][29]. A similar gradual decrease must have occurred in other European countries as well.Slovakia has extensive published data on wild food plant use in the 19th and 20th century, but lacks a comprehensive review of them, apart from a short entry in a dictionary of folk culture [31] and three short essays with only a few literature references [32][33][34]. Hence a review of Slovak publications concerning this topic became the aim of the study.
Material and methods
Slovakia -its flora, geography and historySlovakia covers an area of 49 thousand km