Laetiporus sulphureus
Common names include Sulpher Shelf (because of color and growth habit) and
Chicken Mushroom (because it taste like chicken). Sought out by many in the
summer and fall. Pore surface yellow. Grows from wood.
See Laetiporus sulphureus at
George Barron's Website on Fungi
INDIANA MUSHROOMS  
Very young fruit body.
Laetiporus sulphureus forms fan shaped shelves.
These three images show a time lapse of the same fruiting at different levels of maturity.