Dryopteris

  • Authority

    Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

  • Family

    Dryopteridaceae

  • Scientific Name

    Dryopteris

  • Description

    Genus Description - Terrestrial (rarely epiphytic); rhizomes usually stout, erect or ascending, or sometimes short-creeping, scaly; fronds generally medium-sized, erect or arching, generally clumped, usually monomorphic (ours) to subdimorphic, not articulate; stipes stramineous to reddish brown, in cross section with numerous vascular bundles arranged in a U-shape, the two adaxial bundles the largest, stipes scaly at bases and often distally; blades thin to coriaceous, pinnate-pinnatifid to 3-pinnate-pinnatifid (1-pinnate in a few extraterritorial species), deltate to ovate or lanceolate, broadest at base or above the base, anadromous at bases, main axes decurrent onto major ones, grooved adaxially and with the grooves continuous from one axis to the next; segments entire to toothed or spinulose, abaxially glabrous, glandular, or scaly; veins free, ending short of margins; sori abaxial, round, indusia reniform or round-reniform, each attached at a sinus, ± entire, glabrous or glandular, paraphyses absent; spores bilateral, with a variously winged perispore; x=41.

  • Discussion

    Type: Dryopteris filix-mas (L.) Schott [= Polypodium filix-mas L.].

    Dryopteris comprises about 225 species (Fraser-Jenkins, 1986), largely of north-temperate regions; relatively few species occur at high elevations in the tropics. Most species of Dryopteris are from southern and eastern Asia and the Himalayan region, but about 30 occur in the New World. Species have been grouped into four subgenera and 16 sections by Fraser-Jenk. (1986), but only subg. Dryopteris (Mexican species represented in four sections) and subg. Nephrocystis (H. Itoˆ) Fraser-Jenkins (D. futura) occur in Mexico. Dryopteris nubigena was left unplaced by Fraser-Jenkins, but it is closely related to D. futura; Dryopteris rossii and D. knoblochii were also unplaced but belong in sect. Cinnamomeae Fraser-Jenk. Unlike many Asian species, the American ones do not seem predisposed to apogamy. Two especially problematic species complexes occur in Mexico: one at high elevations (including D. wallichiana, D. pseudofilix-mas; in sect. Fibrillosae Ching and sect. Dryopteris, respectively, in the classification of Fraser-Jenkins, 1986), the other at low to middle elevations (including D. patula, D. cinnamomea, and relatives; sect. Cinnamomeae Fraser-Jenk.). Both complexes need monographic study. Dryopteris is closely allied to Arachniodes, but is distinct in its less divided blades and segments lacking mucronate tips. There is also a close relationship to Polystichum and Phanerophlebia, from which Dryopteris differs in the round-reniform indusia (vs. peltate) and generally more dissected blades. An intergeneric hybrid is known between Dryopteris goldiana (Hook. ex Goldie) A. Gray and Polystichum lonchitis (L.) Roth (= xDryostichum singulare W. H. Wagner) from Ontario, Canada (Wagner et al., 1992). Hybridization is a well known phenomenon in Dryopteris of temperate regions, and may also be common between sympatric species in tropical and subtropical areas. At least two interspecific hybrid combinations are known in Mexico, involving D. pseudofilix-mas x wallichiana and D. cinnamomea x knoblochii, and others are likely.