The only safe edible fern - eaten at the "fiddlehead" stage - is the Ostrich fern. Unless you're sure that's what you have, I wouldn't eat them.

This is the Diplazium esculentum.
Mike

Heres a pic.

Here is a link that might be useful: vegetable fern

Here's an article that mentions them.

Here is a link that might be useful: Fiddlehead Info

I tried ostrich fern fiddleheads this spring and thought they were okay.

They reminded me of over-cooked asparagus (after cooking them for the prescribed 10 minutes of boiling). Back in the 1990's a few people got sick on the east coast after eating ostrich fiddleheads that had been "under-cooked" in restaraunts, so a recommendation was created that you need to boil them for at least 10 minutes.

While researching ostrich ferns I read somewhere that ostrich fiddleheads are the Vermont State vegetable.

You need to be careful to insure you have the correct variety... since there are at least 3 look-alike varieties that have cancer causing chemicals in them and are not recommended for consumption.
Key indicators that it is an ostrich fern (that I can remember off the top of my head) are:
* Grows in a clump
* Tends to like boggy soil (especially in my yard)
* Grow to something like 4 feet tall
* (IMPORTANT) There is a groove in the fern stalk
* In the fall they send up a nicely colored fern head for seed production or something
* Deciduous (dies back in winter)

After buying an Ostrich fern from a nursery and educating myself more about them, I discovered that I had at least 30 mature plants growing wild in my yard. :)

I find the ostrich ferns to be a bit more delicate then the other varieties that grow wild in my yard.... in that the stalks tend to break much more easily.

The company website shown below sells Fiddleheads, Morels, & Ramps fresh in season; frozen Fiddleheads & dried Morels year-round.

While I haven't purchased any of the above from them, I have purchased other gourmet items from them & the quality/shipping/etc. is very good.

Here is a link that might be useful: Earthly Delights

Hmmmm. I think I have a large wild fern that makes fiddleheads and are pretty much exactly like you discribe Divaqs. I'll need to look and see if it has that groove. Hmmmm. boy I'll need to find me a local expert on these and take a piece in for IDing before putting on my dinner plate ;o)
Ha!!! I do have ramps! They are small but some strong!! ;o)
Still not much info on the vegetable fern to be found :o( Oh well I'll keep ....er .... diggin' ;o)
Mike

Also, I should point out that the recommended time to harvest ostrich fiddle heads is in late spring (i.e. April) and to be careful to not over harvest, or it will damage the plant (like asparagus).

I've heard of people freezing or canning the fiddle heads... though personally none of mine have made it that far and have just been consumed. :)