Pteridium aquilinum - Images and description from Montara mountain, California. Southwest Colorado Wildflowers - Image and description of Pteridium aquilinum. Bracken Fern Carcinogenicity - Summary of data reported and evaluation of bracken fern and some of its constituents. Pteridium aquilinum (Bracken) - Images and 10km distribution map for this species. From Flora of Northern Ireland. Pteridium aquilinum - Species information from the U.S. Department of Agriculture/Forest Service's Fire Effects Information System. Pteridium aquilinum - Photograph and detailed description of bracken. Toxicity - P. aquilinum page from "Poisonous Plants of North Carolina" by Dr. Alice B. Russell.