Western Bracken Fern (Pteridium aquilinum)

CA 2011
Western Bracken Fern according to:
http://plants.usda.gov/core/profile?symbol=PTAQ
although it grows all over the US
compare to:
Northern Bracken Fern (Pteridium aquilinum (L.) Kuhn var. latiusculum (Desv.) Underwood ex Heller)
http://www.delawarewildflowers.org/plant.php?id=1601
and one more latiusculum:
http://plants.usda.gov/java/largeImage?imageID=ptla_001_ahp.tif