1	"Leaf blade midrib adaxially glabrous, blade +- membranous to leathery, not fleshy"	2
1	"Leaf blade midrib adaxially hairy, if glabrous, blade membranous to fleshy, not leathery, often firm"	3
2	"Leaf segment generally < 2.5 cm, generally < 1 cm wide; leaf blade +- membranous to +- thick, not leathery, +- firm, not brittle; sori 1--2.5 mm"	"Polypodium hesperium"
2	"Leaf segment 2.5--7(10) cm, 0.9--1.8(2.5) cm wide; leaf blade thick, leathery, firm, brittle; sori 2--6 mm"	"Polypodium scouleri"
3	"Veins free; sori generally round"	"Polypodium glycyrrhiza"
3	"Veins free and fused; sori round to generally ovate or oblong"	4
4	"Leaf blade deltate to ovate, often +- irregular in outline, lower 1--3 segment pairs often >= those above; sori generally +- sunken, round to generally ovate; CCo, SCoRO, SW"	"Polypodium californicum"
4	"Leaf blade oblong-ovate, +- regular in outline, lower 1--3 segment pairs generally < those above; sori not sunken, ovate to oblong; NW (except NCoRH), CaRF, SN (except s SNF), GV (rare), CW"	"Polypodium calirhiza"