Pellaea intermedia |
Pellaea lyngholmii |
|
---|---|---|
creeping cliff brake, intermediate cliffbrake |
lyngholm's 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. |
compact, ascending, stout, 5–10 mm diam.; scales uniformly brown or tan, linear-subulate, 0.1–0.3 mm wide, thin, margins entire to denticulate. |
Leaves | monomorphic, widely scattered along stem, 12–50 cm; croziers pubescent and bearing a few scales. |
somewhat dimorphic, sterile leaves shorter and less divided than fertile leaves, clustered on stem, 10–30 cm; croziers villous. |
Petiole | straw-colored, tan, or gray, not lustrous, rounded or slightly flattened adaxially, without prominent articulation lines. |
dark brown to reddish purple, lustrous, rounded 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. |
elongate-deltate to ovate, 2-pinnate proximally, 5–15 cm wide; rachis brown or reddish purple throughout, straight, often slightly flattened adaxially, sparsely villous with long, divergent hairs. |
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. |
oblong-lanceolate, 7–25 mm, leathery, sparsely villous abaxially near midrib; margins usually recurved on fertile segments, covering less than 1/2 abaxial surface, borders whitish, crenulate; apex 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. |
perpendicular to rachis or slightly ascending, not decurrent on rachis, usually with 7–15 ultimate segments; costae straight, 25–80 mm, usually longer than ultimate segments. |
Veins | of ultimate segments obscure. |
of ultimate segments obscure. |
Sporangia | short-stalked, containing 32 spores, not intermixed with farina-producing glands. |
long-stalked, containing 32 spores, not intermixed with farina-producing glands. |
n | = 2n = 87, 116, apogamous. |
|
Pellaea intermedia |
Pellaea lyngholmii |
|
Phenology | Sporulating summer–fall. | Sporulating summer–fall. |
Habitat | Rocky slopes and ledges, on a variety of substrates, including limestone and granite | Rocky slopes and ledges, usually on sandstone |
Elevation | 300–2400 m (1000–7900 ft) | 1200–1800 m (3900–5900 ft) |
Distribution |
AZ; NM; TX; n Mexico
|
AZ |
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.) |
Pellaea lyngholmii is an apogamous tetraploid that arose through hybridization between P. atropurpurea and P. truncata (M. D. Windham 1993). It is most often confused with P. atropurpurea, from which P. lyngholmii differs in having sparsely villous rachises, smaller and more numerous ultimate segments, and spores usually more than 62 µm in diameter. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Pteridaceae > Pellaea | Pteridaceae > Pellaea |
Sibling taxa | ||
Synonyms | P. intermedia var. pubescens | |
Name authority | Mettenius ex Kuhn: Linnaea 38: 84. (1869) | Windham: Contr. Univ. Michigan Herb. 19: 40. (1993) |
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