Click the number at the start of a key lead to highlight both that lead and its corresponding lead. Click again to show only the two highlighted leads. Click a third time to return to the full key with the selected leads still highlighted.
1 Leaves 1-pinnate-pinnatifid to 2-pinnate; sori distinct.
..2 Leaf blade broadest near its midpoint, strongly narrowing towards base; pinnae outline oblong, with parallel margins for 1/2 to 3/4 of its length; [native, ec. PA northwards]
..2 Leaf blade widest at base or 2-4 pinnae above the base; pinnae outline narrowly triangle, with margins angled towards the narrowly acuminate tip; [rare, exotic]
....3 Rachis densely pubescent with shaggy, orange to red pubescence