Pellaea mucronata

(D. C. Eaton) D. C. Eaton in Emory

in Emory,Rep. U.S. Mex. Bound. 2(1): 233. 1859.

Basionym: Allosorus mucronatus D. C. Eaton Amer. J. Sci. Arts 22: 138. 1856
Synonyms: Pellaea ornithopus Hooker
Treatment appears in FNA Volume 2. Treatment on page 182.

Stems compact, ascending, stout, 5–10 mm diam.; scales bicolored, linear-subulate, 0.1–0.3 mm wide, centers black, thick, margins brown, thin, erose-dentate. Leaves monomorphic, clustered on stem, 7–45 cm; croziers sparsely villous. Petiole dark-brown, lustrous, flattened to slightly grooved adaxially, without prominent articulation lines. Blade ovate-deltate, (2–) 3-pinnate proximally, 4–18 cm wide; rachis brown throughout, straight, shallowly grooved adaxially, usually glabrous. Pinnae perpendicular to rachis to strongly ascending, not decurrent on rachis, usually with 9–40 ultimate segments; costae straight, 10–70 mm, much longer than ultimate segments. Ultimate segments narrowly oblong, 2–12 mm, leathery, glabrous; margins recurved to strongly revolute on fertile segments, usually covering more than 1/2 abaxial surface, borders greenish, usually dentate; apex mucronate. Veins of ultimate segments obscure. Sporangia short-stalked, containing 64 spores, intermixed with abundant farina-producing glands.

Discussion

Subspecies 2 (2 in the flora).

Pellaea mucronata encompasses two morphologic extremes that tend to occupy different habitats and are treated here as subspecies. The typical 3-pinnate form (P. mucronata subsp. mucronata) is scattered throughout California and southern Nevada, usually below 1800 m elevation. The 2-pinnate form with ascending, overlapping pinnae (P. mucronata subsp. californica) is apparently confined to the Sierra Nevada and Transverse Ranges of California at elevations greater than 1800 m. The taxonomic status of these entities remains in dispute, and they are often treated as mere ecological forms. W. H. Wagner Jr. et al. (1983) indicated that natural hybrids formed between P. bridgesii and these two taxa are morphologically distinct, suggesting that the differences observed between the subspecies of P. mucronata are genetically based. In addition to P. bridgesii, subsp. mucronata apparently hybridizes with both P. truncata and P. brachyptera (see comments under those species).

Selected References

None.

Key

1 Blades 3-pinnate proximally; pinnae usually ± perpendicular to rachis, not overlapping; plants usually found below 1800 m. Pellaea mucronata subsp. mucronata
1 Blades usually 2-pinnate proximally; pinnae ascending and overlapping, especially in distal portion of leaf; plants usually found above 1800 m. Pellaea mucronata subsp. californica

"thick" is not a number.

... more about "Pellaea mucronata"
Michael D. Windham +
(D. C. Eaton) D. C. Eaton in Emory +
cordate +, truncate +  and rounded +
Allosorus mucronatus +
glabrous +  and pubescent +
ovate-deltate +
4cm;18cm +
straight +
Calif. +, Nev. +  and Mexico +
yellow +  and white +
obcordate;reniform +
monomorphic +
clustered;widely scattered +
recurved +  and reflexed +
noncircinate +  and circinate +
7 cm70 mm <br />0.07 m <br /> (45 cm450 mm <br />0.45 m <br />) +
entire +, erose +  and dentate +
pubescent +  and glabrous +
flattened +
perpendicular +
in Emory,Rep. U.S. Mex. Bound. +
persistent +
linear-subulate +
0.1mm +  and 0.3mm +
brown +  and tan +
cristate +  and tetrahedral-globose +
dark colored +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Pellaea ornithopus +
Pellaea mucronata +
species +
0.2 cm2 mm <br />0.002 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
crescent--shaped +  and roundish +
branched +  and anastomosing +