Ethnobotanical survey on wild alpine food plants in Lower and Central Valais (Switzerland).

ETHNOPHARMACOLOGICAL RELEVANCE: Swiss Alps have an ancestral tradition with regard to the use of wild plants as medicines and food. However, this knowledge is falling into oblivion, and is nowadays confined to village areas. Aim of the study was to identify wild edible plants used today and during the last two centuries by the alpine population of Valais (Switzerland). MATERIAL AND METHODS: Data were collected by means of semi-directed interviews made in four different lateral valleys of Valais (Val d'Anniviers, Val d'Entremont, Val d'Hérens, and Val d'Illiez). Wild food plants were classified according to their uses (salads, cooked vegetables, spices, raw snacks, teas, alcoholic drinks, sirups, and jams). Books and reports written in the XIXth century were consulted to identify uses of wild plants which have fallen in oblivion meanwhile. RESULTS: A total of 98 edible wild plants, distributed into 38 botanical families, were identified during the interviews. Several plants were highly cited (e.g. Taraxacum officinale, Chenopodium bonus-henricus). The most frequent usage was as tea (18%), followed by uses as cooked vegetables (16%), jams (16%), and raw snacks (16%). A strong association was observed between food and medicinal uses of plants. Wild food plants were of critical importance in times of food scarcity. Meanwhile, they have lost their relevance as vital components of the diet and are nowadays rather perceived and appreciated as delicacies. CONCLUSIONS: This study provides for the first time comprehensive data on present day and historical uses of wild plants as food in Lower and Central Valais. Besides being of historical interest, this ethnobotanical information can be used to identify species which may provide interesting opportunities for diversification of mountain agriculture.

Comparison of volatile constituents of Persicaria odorata(Lour.) Soják (Polygonum odoratum Lour.) and Persicaria hydropiper L. Spach (Polygonum hydropiper L.).

Polygonum odoratum Lour. has been reclassified as Persicaria odorata (Lour.) Soják [Wilson, K. L. Polygonum sensu lato (Polygonaceae) in Australia. Telopea 1988, 3, 177-182]; other synonyms currently used are Vietnamese mint or Vietnamese coriander and, in Malaysia, Daun Laksa or Laksa plant. The aerial parts of Laksa plant are highly aromatic, and they contain many organic compounds such as (Z)-3-hexenal, (Z)-3-hexenol, decanal, undecanal, and dodecanal that are typical for green, citrus, orange peel, and coriander odors. In addition to these aldehydes, 3-sulfanyl-hexanal and 3-sulfanyl-hexan-1-ol were discovered for the first time in this herb. The fresh leaves are pungent when they are chewed, although the active compound has never been identified. The pungency of Persicaria hydropiper (L.) Spach (formerly Polygonum hydropiper L., synonym water pepper) is produced by polygodial, a 1,4-dialdehyde derived from drimane terpenoids. We also identified polygodial as the active pungent compound in P. odorata (Lour.) Soják.