Hodge W. H. 1973. Fern foods of Japan and the problem of toxicity. American Fern Journal 63(3): 77-80
Notes
The tender croziers of bracken (and some other ferns) are a well known and popular wild vegetable food in Japan. Called "warabi". The rhizomes are also sometimes used for starch or for making paste. The Japanese made selections of the superior bracken strains late last century and these are still maintained in cultivation. Croziers briefly boiled with wood ash or sodium bicarbonate to remove the bitterness. Again boiled, served with flavourings. Also salted, dried, pickled. The author discusses work done on the strong carcinogenic effects of bracken. Boiling with wood ash, etc. reduced the carcinogenity to 25%. Variation also exists in carcinogenic activity of bracken from different parts of Japan.
Bibliographic details
Fern foods of Japan and the problem of toxicity