1. Vegetative blades simple, entire; sporangia imbedded in the rachis of a spike.
1. Vegetative blades pinnately lobed, dissected, or even more compounded (except in extremely depauperate individuals); sporangia fully exposed, often on a branched structure.
2. Vegetative blades persisting over winter; blades with distinct petiole, usually 5–25 cm long in fertile individuals, but dwarfed plants occasional, leaf texture somewhat leathery; vegetative individuals common in populations; fertile portion of leaf joining the vegetative portion at or near ground level.
2. Vegetative blades (and entire plant) deciduous; blades usually ± sessile, large (>>5cm) or much smaller, membranous, herbaceous, or sometimes ± succulent in texture; most individuals in populations fertile; fertile portion of leaf joining the vegetative portion well above ground level.
3. Vegetative blades deltate, 3–4x pinnate, sessile and mostly 5–25 cm broad; fertile portion of blade erect , suggesting a continuation of the common stalk.
3. Vegetative blades short-deltate, oblong, or linear, lobed (simple) to 3-pinnate (typically 1-pinnate to 2-pinnate pinnatifid), 1–5 (–10) cm broad; fertile portion of blade frequently ascending, spreading, or even perpendicular to the common stalk.