Polypodium christensenii Maxon
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Authority
Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.
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Family
Polypodiaceae
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Scientific Name
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Description
Species Description - Rhizomes creeping, 3–4 mm diam.; rhizome scales orange-tan, lanceolate, attenuate, the margins inrolled, entire, 6–7 x 1–1.2 mm; fronds 65–120 cm long, 1 cm or more distant; stipes 1/4–1/2 the frond length, dark brown, with short, whitish hairs, 0.1 mm; blades pinnatisect, apices usually pinnatifid to blade tips, narrowly oblong, 15–30 cm wide; pinnae 23–30 pairs, broadly adnate to rarely narrowly adnate proximally, linear, 7–18 cm x 1.4–2.2 mm; margins crenulate-serrulate; abaxial surfaces with dense erect hairs ca. 0.5 mm long, hairs on costae 0.6–1 mm; adaxial surfaces with hairs ca. 0.5 mm long; venation free, with rare anastomoses, vein ends conspicuous; sori round, medial; sporangia with hairs 0.1 mm; 2n=74 (Chis).
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Discussion
Type. Guatemala. Alta Verapaz: near Coba´n, Tu¨rckheim II 2179 (US!; isotypes BR!, NY!, US! frag. UC!).
Polypodium christensenii is very similar to P. puberulum but seems to differ in the larger fronds to 1.2 m long; stipes dark brown; pinnae irregularly crenulate-serrate along margins; and perhaps in rhizome scales without a greatly expanded base, not as long-attenuate, spreading. This group of free-veined, hairy polypodiums (including P. subpetiolatum) is badly in need of revision.
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Distribution
Epiphytic or on mossy banks, margins of montane rain forests, evergreen cloud forests; 2000–2400 m. Mexico; Guat.
Guatemala Central America| México Mexico North America|