Pellaea ternifolia

(Cavanilles) Link

Fil. Spec. 59. 1841.

Basionym: Pteris ternifolia Cavanilles Descr. Pl., 266. 1802
Treatment appears in FNA Volume 2. Treatment on page 180.

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, 10–50 cm; croziers sparsely to densely villous. Petiole black or dark purple, lustrous, rounded or slightly flattened adaxially, without prominent articulation lines. Blade linear to ovate, deeply pinnate-pinnatifid proximally, 2.5–8 cm wide; rachis black or purple throughout, straight, often flattened adaxially, glabrous or villous. Pinnae perpendicular to rachis or slightly ascending, not decurrent on rachis, ternate at base of leaf; costae absent. Ultimate segments linear-oblong, 10–40 mm, leathery, glabrous to sparsely villous abaxially on midrib; margins recurved on fertile segments, rarely covering more than 1/2 abaxial surface, borders whitish, entire; apex mucronate. Veins of ultimate segments obscure. Sporangia long-stalked, containing 64 spores, not intermixed with farina-producing glands.


Ariz., Tex., Mexico, Central America, South America, Pacific Islands in Hawaii


Subspecies 3 (3 in the flora).

Pellaea ternifolia is represented in the flora by three morphologically and chromosomally distinct taxa. These discrete genetic entities also show a tendency toward geographic isolation and are treated here as subspecies. Diploid populations referred to P. ternifolia subsp. ternifolia are scattered from Texas through Mexico to South America. The pubescent tetraploid (P. ternifolia subsp. villosa) follows the Sierra Madre Oriental from Puebla, Mexico, north to Texas; the glabrous tetraploid (P. ternifolia subsp. arizonica) occurs in Arizona, Texas, and northern Mexico. Isozyme and chromosome studies suggest that both tetraploids are segmental allopolyploids produced by hybridization between subsp. ternifolia and other (as yet unidentified) diploid elements within P. ternifolia.

Selected References



1 Rachises villous, especially in axils of pinnae; pinnae with hairs scattered along main veins abaxially. Pellaea ternifolia subsp. villosa
1 Rachises glabrous or with a few widely scattered hairs; pinnae completely glabrous. > 2
2 Largest ultimate segments (excluding terminal pinnae) usually less than 18 mm; distal portion of petioles grooved or flattened adaxially; spores usually 39–45 µm diam. Pellaea ternifolia subsp. ternifolia
2 Largest ultimate segments (excluding terminal pinnae) usually more than 18 mm; distal portion of petioles rounded or slightly flattened adaxially; spores usually 46–53 µm diam. Pellaea ternifolia subsp. arizonica

"thick" is not a number.

... more about "Pellaea ternifolia"
Michael D. Windham +
(Cavanilles) Link +
cordate +, truncate +  and rounded +
Pteris ternifolia +
glabrous +  and pubescent +
pinnate-pinnatifid +, linear +  and ovate +
2.5cm;8cm +
Ariz. +, Tex. +, Mexico +, Central America +, South America +  and Pacific Islands in Hawaii +
yellow +  and white +
obcordate;reniform +
monomorphic +
clustered;widely scattered +
recurved +  and reflexed +
noncircinate +  and circinate +
10 cm100 mm <br />0.1 m <br /> (50 cm500 mm <br />0.5 m <br />) +
entire +, erose +  and dentate +
dark purple;black +
pubescent +  and glabrous +
flattened +  and rounded +
perpendicular +
purple +  and black +
villous +  and glabrous +
not decurrent +  and flattened +
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 ternifolia +
species +
glabrous;sparsely villous +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
crescent--shaped +  and roundish +
branched +  and anastomosing +