Key to Pteridaceae

View taxon page for Pteridaceae

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Leaves of 2 kinds, fertile more 

erect 

Upright; vertically oriented.

, with longer stipes, longer, narrower segments than sterile ..... CRYPTOGRAMMA

1' Leaves of ± 1 kind (in Aspidotis densa fertile, sterile ± dissimilar)

2. Leaf segment margin generally not 

recurved 

Gradually curved downward or backward.

, ± unmodified, not covering sporangia; sporangia along veins

3. Leaf 1-pinnate; 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

adaxially glabrous or with scales

4. Pinna adaxially with 

stellate 

Pertaining to a hair or other structure with three or more branches radiating in two or three dimensions from a common point.

scales, margins shallowly (not deeply) pinnately lobed or dissected or not ..... ASTROLEPIS

4' Pinna adaxially glabrous, margins ± wavy, not lobed or dissected ..... Pellaea bridgesii

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. Sporangia along veins for outer 1/3–2/3; leaf segments narrowed at base ..... ARGYROCHOSMA (2)

5' Sporangia along veins ± throughout (best seen on immature, fertile leaf); leaf segments not narrowed at base ..... PENTAGRAMMA

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. Sporangia borne on and covered by highly modified, recurved part of segment margin (false indusium); segments fan-shaped or 

oblong 

Longer than wide, with nearly parallel sides; wider than linear.

, 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 

Narrowly elongate, widest in the basal half, often tapered to an acute tip.

, round, or other, generally thick-textured

7. Leaf generally > 40 cm, stipe green to brown, ± thick ..... PTERIS

7' Leaf generally < 40 cm, if larger, stipe ± black and wiry (except in Pellaea andromedifolia)

8. Leaf abaxially with scales, hairs, or glands ..... MYRIOPTERIS

8' Leaf abaxially glabrous or covered with colored exudate, scales 0

9. Leaf abaxially densely covered with white or yellow exudate, adaxially sparsely dotted with same ..... NOTHOLAENA

9' Leaf without exudate (except some species of Pellaea and abaxially in Argyrochosma limitanea)

10. Sterile leaf segments ± 

sessile 

Without a petiole, peduncle, pedicel, or other kind of stalk.

, connected by 

blade 

Expanded portion of a leaf, petal, or other structure, generally flat but sometimes rolled, cylindric, wavy, or cupped.

tissue or not, toothed or not; false 

indusium 

In many ferns, a veil- or scale-like outgrowth of the leaf surface that covers a sorus.

wide, scarious ..... ASPIDOTIS

10' Sterile leaf segments (and fertile) stalked (except Pellaea breweri), not connected by blade tissue, not toothed; false indusium 0 or narrow or wide, scarious, not scarious, or ± scarious at margin

11. Sporangia along veins for outer 1/3–2/3; 

rhizome 

1. In seed plants, stem that is often elongate, more or less horizontal, usually underground; distinguished from roots by bearing of leaves, leaf scars, axillary buds, etc. 2. In ferns, stem that is located underground, embedded in leaf litter, on rocks or in rock crevices, or on trees or tree branches, often scaly or hairy; distinguished from roots by bearing of fronds (roots rarely bear fronds), and their greater diameter.

scales without dark mid-stripe; false indusium 0 ..... ARGYROCHOSMA (2)

11' Sporangia along veins only at tips; rhizome scales often with dark mid-stripe; false indusium present (except Pellaea bridgesii) ..... PELLAEA

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