Thank you to Stephen B of Scotland aka stephenbuchan@Flickr for another couple photographs shared with BPotD (original 1 | original 2 | BPotD Flickr Pool). As always, it is very much appreciated, Stephen.
Bracken fern can be found throughout most of the world. The advantage of featuring one of the most widely distributed vascular plants is that there is a wealth of information online.
On its classification: Is it one species with many subordinate taxa (i.e., subspecies and varieties)? Or is there now enough evidence to break up the one species into ten or so distinct species? The Flora of North America’s entry on Pteridium aquilinum notes the “disagreement existing among taxonomists” with a summary of evidence pointing to splitting up the one species into multiples, but still opts for a single-species approach. This illustration from the Flora of North America shows the variability of form between taxa.
On edibility: The Plants for a Future database, as always, details the edibility and other economic uses, but accompanies it with a warning about potential health risks of ingestion. The Nova Scotia Museum simply labels it carcinogenic, with the suggestion that it is to be avoided. Wikipedia summarizes how bracken is used (and eaten) by several cultures.