The present - day popularity of fiddlehead greens has made them readily available, frozen and canned, in many gourmet food stores. However, the bracken fern is listed as being poisonous to livestock, at least to some degree. Many varieties of the plant produce equivalent poisoning. Serious livestock loss has occurred in many states. Large amounts of bracken are required to produce symptoms in horses.
Sheep are more resistant than cattle to bracken poisoning.
The mature leaves, especially in hay, seem to be the offenders. But it has been shown that young bracken has the nutritive value equivalent to good hay. A legend warns that anyone inclined to gather the spores of this fern on Saint john's Eve will become invisible if he holds them in his hand at the moment of the Saint's birth. The plant forms large patches resembling a miniature pine forest and is quite attractive. Both cypress spurge and E. corollata L., sometimes called flowering spurge, are still cultivated occasionally but can be a potential danger to children if eaten.