1	"Leaves of 2 kinds, fertile more erect, with longer stipes, longer, narrower segments than sterile"	Cryptogramma
1	"Leaves of +- 1 kind (in <i>Aspidotis densa</i> fertile, sterile +- dissimilar)"	2
2	"Leaf segment margin generally not recurved, +- unmodified, not covering sporangia; sporangia along veins"	3
2	"Leaf segment margin generally recurved at least partly, often modified, generally covering sporangia at least partly; sporangia at or near vein tips, so appearing marginal"	6
3	"Leaf 1-pinnate; leaf adaxially glabrous or with scales"	4
3	"Leaf either 1-pinnate with pinnae pinnately dissected or leaf generally more divided; leaf adaxially glabrous, glandular, or +- covered with exudate, scales 0"	5
4	"Pinna adaxially with stellate scales, margins shallowly (not deeply) pinnately lobed or dissected or not"	"Astrolepis {Astrolepis cochisensis}"
4	"Pinna adaxially glabrous, margins +- wavy, not lobed or dissected"	"Pellaea bridgesii"
5	"Sporangia along veins for outer 1/3--2/3; leaf segments narrowed at base"	Argyrochosma
5	"Sporangia along veins +- throughout (best seen on immature, fertile leaf); leaf segments not narrowed at base"	Pentagramma
6	"Sporangia borne on and covered by highly modified, recurved part of segment margin (false indusium); segments fan-shaped or oblong, thin-textured"	Adiantum
6	"Sporangia borne on unmodified segment surface, generally covered at least partly by modified or unmodified, recurved part of segment margin (false indusium); segments lanceolate, round, or other, generally thick-textured"	7
7	"Leaf generally > 40 cm, stipe green to brown, +- thick"	Pteris
7	"Leaf generally < 40 cm, if larger, stipe +- black and wiry (except in <i>Pellaea andromedifolia</i>)"	8
8	"Leaf abaxially with scales, hairs, or glands"	Myriopteris
8	"Leaf abaxially glabrous or covered with colored exudate, scales 0"	9
9	"Leaf abaxially densely covered with white or yellow exudate, adaxially sparsely dotted with same"	"Notholaena {Notholaena californica}"
9	"Leaf without exudate (except some species of <i>Pellaea</i> and abaxially in <i>Argyrochosma limitanea</i>)"	10
10	"Sterile leaf segments +- sessile, connected by blade tissue or not, toothed or not; false indusium wide, scarious"	Aspidotis
10	"Sterile leaf segments (and fertile) stalked (except <i>Pellaea breweri</i>), not connected by blade tissue, not toothed; false indusium 0 or narrow or wide, scarious, not scarious, or +- scarious at margin"	11
11	"Sporangia along veins for outer 1/3--2/3; rhizome scales without dark mid-stripe; false indusium 0"	Argyrochosma
11	"Sporangia along veins only at tips; rhizome scales often with dark mid-stripe; false indusium present (except <i>Pellaea bridgesii</i>)"	Pellaea