Pellaea cordifolia

Stems compact, ascending, stout, 6–10 mm diam.; scales uniformly orange-brown and thin, lanceolate to ovate, largest scales 0.3–1 mm wide, margins dentate. Leaves somewhat dimorphic, sterile leaves shorter than fertile leaves, clustered on stem, 15–50 cm; croziers not conspicuously pubescent, densely scaly. Petiole straw-colored, tan, or gray, not lustrous, rounded or slightly flattened adaxially, without prominent articulation lines. Blade ovate-deltate, 2-pinnate proximally, 5–20 cm wide; rachis tan throughout, straight to slightly flexuous, rounded or flattened adaxially, glabrous. Pinnae perpendicular to rachis or slightly ascending, not decurrent on rachis, usually with 3–15 ultimate segments; costae straight to slightly flexuous, 25–100 mm, longer than ultimate segments. Ultimate segments round-cordate to deltate-cordate, 5–15 mm, herbaceous to leathery, glabrous or puberulent; margins recurved on fertile segments, covering less than 1/2 abaxial surface, borders whitish, crenulate; apex rounded or retuse. Veins of ultimate segments usually evident. Sporangia short-stalked, containing 64 spores, not intermixed with farina-producing glands. 2n = 58.

Phenology: Sporulating summer–fall.
Habitat: Rocky slopes and ledges, usually on volcanic substrates
Elevation: 1000–2500 m

Tex., Mexico.

Discussion

The diploid Pellaea cordifolia has often been treated as a variety of the Central American and South American apogamous triploid, P. sagittata. The two taxa are distinguished by a number of qualitative morphologic features (A. R. Smith 1980), and it seems unlikely that they represent cytotypes of a single species. A. F. Tryon (1957) suggested that P. sagittata may have originated through hybridization between P. ovata and P. cordifolia (as P. sagittata var. cordata).

Selected References

None.

Lower Taxa