Key to Polypodium

View taxon page for Polypodium

(For a list of species in Polypodium, use the above link.)

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

1. Leaf 

blade 

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

midrib adaxially glabrous, blade ± membranous to leathery, not fleshy

2. Leaf segment generally < 2.5 cm, generally < 1 cm wide; 

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).

blade ± membranous to ± thick, not leathery, ± firm, not brittle; sori 1–2.5 mm ..... P. 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 ..... P. scouleri

1' Leaf blade midrib adaxially hairy, if glabrous, blade membranous to fleshy, not leathery, often firm

3. Veins free; sori generally round ..... P. glycyrrhiza

3' Veins free and fused; sori round to generally 

ovate 

Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf.

or 

oblong 

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

4. Leaf blade 

deltate 

More or less equilaterally triangular, with the corners rounded or not.

to ovate, often ± irregular in outline, lower 1–3 segment pairs often >= those above; sori generally ± sunken, round to generally ovate; CCo, SCoRO, SW ..... P. 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 ..... P. calirhiza

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