Pellaea intermedia |
|
---|---|
creeping cliff brake, intermediate cliffbrake |
|
Stems | creeping, horizontal, slender, 2–4 mm diam.; scales mostly bicolored, narrowly lanceolate, largest scales 0.3–0.8 mm wide, centers black, thick, margins brown, thin, irregularly dentate. |
Leaves | monomorphic, widely scattered along stem, 12–50 cm; croziers pubescent and bearing a few scales. |
Petiole | straw-colored, tan, or gray, not lustrous, rounded or slightly flattened adaxially, without prominent articulation lines. |
Blade | ovate to elongate-deltate, usually 2-pinnate proximally, 4–20 cm wide; rachis tan throughout, straight to slightly flexuous, rounded or flattened adaxially, ± pubescent. |
Ultimate segments | ovate to elliptic, 5–15 mm, leathery, glabrous or usually puberulent abaxially; margins recurved on fertile segments, usually covering less than 1/2 abaxial surface, borders whitish, nearly entire; apex obtuse to slightly mucronate. |
Pinnae | perpendicular to rachis or slightly ascending, not decurrent on rachis, usually with 7–21 ultimate segments; costae straight to slightly flexuous, 20–100 mm, longer than ultimate segments. |
Veins | of ultimate segments obscure. |
Sporangia | short-stalked, containing 32 spores, not intermixed with farina-producing glands. |
n | = 2n = 87, 116, apogamous. |
Pellaea intermedia |
|
Phenology | Sporulating summer–fall. |
Habitat | Rocky slopes and ledges, on a variety of substrates, including limestone and granite |
Elevation | 300–2400 m (1000–7900 ft) |
Distribution |
AZ; NM; TX; n Mexico
|
Discussion | Plants of Pellaea intermedia in the flora are apogamous triploids and tetraploids; a sexual diploid cytotype has been found near Saltillo, Mexico (A. F. Tryon 1968). Given the high degree of morphologic similarity among the three cytotypes, the North American polyploids probably were derived from the Mexican diploid through autopolyploidy. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. |
Parent taxa | Pteridaceae > Pellaea |
Sibling taxa | |
Synonyms | P. intermedia var. pubescens |
Name authority | Mettenius ex Kuhn: Linnaea 38: 84. (1869) |
Web links |