Argyrochosma fendleri Windham
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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
Pteridaceae
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Scientific Name
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Description
Species Description - Rhizomes compact, horizontal to ascending, 2–3 mm diam.; rhizome scales concolorous orange-brown, linear-lanceolate, 7–10 mm; fronds 5–25 cm long, clumped; stipes 1/2 the frond length, castaneous, 0.75–1.5 mm diam., terete, glabrous; blades deltate, 4–6-pinnate proximally; rachises terete, glabrous, strongly flexuous; pinnae 4–5 pairs, costae of pinnae and pinnules strongly flexuous; ultimate segments not articulate, dark color of stalks continuing into segment bases abaxially, coriaceous, covered by whitish farina, adaxially glabrous or with scattered farina; segment margins plane to recurved, often partially concealing sporangia; veins usually obscure adaxially; sori submarginal, borne on distal 1/4 of veins; sporangia 64-spored; 2n=54 (USA).
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Discussion
Notholaena fendleri Kunze, Farrnkra¨uter 2: 87, pl. 136. 1851. Pellaea fendleri (Kunze) Prantl, Bot. Jahrb. Syst. 3: 417. 1882. Cheilanthes cancellata Mickel, Phytologia 41: 433. 1979. Type. U.S.A. New Mexico: Trapp formations of the Rio del Norte near Santa Fe, Fendler 1017a (LZ, destroyed; isotypes B, BM, GH!, K, MO).
Argyrochosma fendleri is distinct by its strongly flexuous rachises and rachillae. Argyrochosma limitanea has slightly flexuous rachises and costae, but the frond axes are not so strongly spreading, and this species is more widespread in Mexico. All specimens of A. limitanea with slightly flexuous rachises and costae have 32 spores per sporangium, whereas specimens of A. fendleri consistently have 64.
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Distribution
Rocky slopes and cliffs, usually on granitic or volcanic substrates; elevation unknown in Mexico, 1700–3000 m in North America. USA (Colo, N Mex, Wyo); Mexico.
Colorado United States of America North America| New Mexico United States of America North America| Wyoming United States of America North America|