Bracken

In the past, the genus was commonly treated as having only one species, Pteridium aquilinum, but the recent trend is to subdivide it into about ten species. Bracken fiddleheads (the immature, tightly curled emerging fronds) have been considered edible by many cultures throughout history, and are still commonly used today as a foodstuff. Bracken fiddleheads are either consumed fresh (and cooked) or preserved by salting, pickling, or sun drying. The plant is carcinogenic to animals such as mice, rats, horses and cattle when ingested, although they will usually avoid it unless nothing else is available. Young stems are quite commonly used as a vegetable in China, Japan and Korea. However, some researchers suspect a link between consumption and higher stomach cancer rates.The spores have also been implicated as a carcinogen. Danish scientist Lars Holm Rasmussen released a study in 2004 showing that the carcinogenic compound in bracken, ptaquiloside or PTQ, can leach from the plant into the water supply, which may explain an increase in the incidence of gastric and esophageal cancers in bracken-rich areas. This information was from wikipedia: http://en.wikipedia.org/wiki/Bracken#Uses