1	Rhizomes stout, compact, short-creeping to suberect, usually 5–8 mm diam. (scales excluded); stipes mostly 1.5–3 mm diam. at bases; laminae palmate-pinnate (fan-shaped), proximal pinna pair 2–3-times basiscopically forked; pinnulets strongly inequilateral, 2–4 times longer than wide	Adiantum aleuticum
–	Rhizomes relatively narrow, short- to long-creeping (occasionally more compact in Adiantum shastense), usually 1.5–3 mm diam (scales excluded); stipes mostly 0.5–1.5 mm diam. at bases; laminae 2–3-pinnate (not fan-shaped), proximal pinna pair 0–1 times basiscopically forked; pinnulets more or less equilateral (bilaterally symmetric), about as long as wide or sometimes to twice as long as wide in Adiantum capillus-veneris.
2	Rhizome and stipe base scales golden brown or light brown; laminae usually 2-pinnate; pinnulets (especially sterile ultimate segments) cut or lobed often >1/4 or much more than (to 2/3) the way to base; dark color of stalks extending into base of ultimate segments; distal teeth of sterile segments usually >3 mm long, acute at tips; pinnulet margins at base diverging at 45–90°; sori (and false indusia) (2–)3–11 per pinnulet, generally < 5 mm long	Adiantum capillus-veneris
–	Rhizome and stipe base scales dark brown or dark purplish brown; laminae 2–3-pinnate, larger fronds with proximal pinnae usually having at least 1 or 2 pairs of pinnules divided (i.e., laminae 3-pinnate proximally); pinnulets (especially sterile ultimate segments) cut or lobed usually <1/4 of the way to base; dark color of stalks extending into base of ultimate segments or ending ± abruptly at base of ultimate segments; distal teeth of sterile segments 1–2(–3) mm long, rounded or acute at tips; pinnulet margins at base diverging at 90–180(–240)°; sori (and false indusia) 1–5 per pinnulet, some generally > 5 mm long.
3	Rhizomes short-to long-creeping, just below soil surface, stipe bases often > 5 mm apart; lamina tissue green; dark color of stalks ending ± abruptly at base of ultimate segments; ultimate segments often somewhat semi-lunate; mature fronds dying in late spring or early summer, completely dried and largely unseen in late summer, fall, and early winter; throughout California, but apparently rare in Shasta Co	Adiantum jordanii
–	Rhizomes short-creeping to suberect, often deeply buried, stipe bases < 5 mm apart; laminar tissue bluish green; dark color of stalks extending into base of ultimate segments; ultimate segments often somewhat rhomboidal; mature fronds persistent and evergreen through summer and into winter and following spring; Shasta Co., locally abundant	Adiantum shastense