Dryopteris patula (Sw.) Underw.

  • 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 patula (Sw.) Underw.

  • Description

    Species Description - Rhizomes erect; rhizome scales concolorous, light brown to often reddish tan, lustrous, (9-)12 -25 x(1.5-)2-3 mm, ovatelanceolate, strongly toothed and twisted; fronds (25-)35-135 cm long; stipes stramineous to tan, 18-35 cm x 2-9 mm, 1/4-1/3 the frond length, scaly near bases with twisted scales to 20 mm, margins toothed, stipes also usually glandular; blades chartaceous, green to yellow-green, deltate-lanceolate, 3-pinnatepinnatifid at bases, otherwise mostly 2-pinnate-pinnatifid, (16- )25-50(-70) x(6.5-)20-40 cm, with pinnae mostly alternate, ascending 45-60º from rachises, 12-20 pairs; rachises stramineous, scaleless or proximally with scattered, tan, linear, twisted scales to 5 x 0.2-0.4 mm, also with minute stipitate glands < 0.1 mm; proximal pinnae ± equilateral to slightly inequilateral, (4-)9-20(-25) x (2-)5-8 cm, shorter than or about equalling the second pinna pair, basiscopic basal pinnule 2-8 cm long, acroscopic basal pinnule 1.8-5.5 cm long; distal pinnae sessile or stalked to 5 mm, subequilateral or usually inequilateral and more developed acroscopically, pinnules of basiscopic side shorter and more oblique, 7-20 x 4-8 cm, pinnules pinnatifid to merely shallowly lobed to toothed; indument abaxially of few to many yellowish stipitate glands 0.1 mm long on costae, veins, and sometimes laminar tissue, scales none, adaxially with glands in costal grooves and also sometimes on surfaces; sori medial to submarginal, indusia brown to tan, 0.8-1.5 mm diam., flat, glabrous or glandular; 2n=82 (Jam).

  • Discussion

    Aspidium patulum Sw., Kongl. Vetensk. Acad. Handl. 1817: 64. 1817. Type. Brazil. Minas Gerais: Freyreiss s.n. (S)..

    Aspidium paupertinum Kunze, Linnaea 18: 345. 1844. Aspidium mexicanum C. Presl var. obtusilobum Kunze ex Mett., Abh. Senckenberg. Naturf. Ges. 2: 349. 1858. Type. Mexico? “Reg. temp. (Herb. Roem., propr) Coll. No. 42.”

    Aspidium apertum Fe´e, Me´m. Foug. 8: 106. 1857. Dryopteris aperta (Fe´e) C. Chr., Index Filic. 252. 1905. Syntypes. Mexico. [Veracruz:] Huatusco, Schaffner 73 (P?); [Morelos:] Cuernavaca, Craveri 73b (P!).

    Dryopteris simplicior Mickel & Beitel, Mem. New York Bot. Gard. 46: 166. 1988. Type. Mexico. Oaxaca: Distrito Putla, 3 km N of Putla, Mickel 3977 (NY!).

    Unverified, Doubtful, or Mistaken Reports. DF (reported by Mickel & Beitel, 1988, but not verified). Me´x (reported by Mickel & Beitel, 1988, but not verified; the chromosome voucher, Mickel 668, ISC, cited by Mickel et al., 1966, as this species is D. rossii; Tejero Di´ez 3002, IZTA, cited by Tejero-Di´ez & Arregui´n-Sa´nchez, 2004, is D. cinnamomea). Sin (reported by Vega A. et al., 1989, probably misidentified).

    The D. patula complex is confused and in need of monographic study.Within this complex in Mexico we recognize four taxa at species rank (D. patula s.str., D. cinnamomea, D. knoblochii, and D. rossii). In the restricted sense, D. patula has deltatelanceolate fronds, long strongly toothed rhizome scales that are marginally crisped and have long, twisted hair-tips, and usually glabrous blade surfaces (except for costal and costular grooves adaxially and sparse glands on the veins abaxially); however, more glandular variants are known, especially along the Pacific slopes of the Sierra Madre Occidental. Dryopteris flaccisquama A. Rojas, recently described from Costa Rica to Bolivia, and Haiti, is merely a very large form of D. patula, and probably not worthy of species distinction. Dryopteris simplicior was said to differ from D. patula primarily in being glandular on the adaxial surfaces of the laminae (vs. glands along only the midribs), pale brown rhizome scales (vs. reddish brown), and proximal pinna pair equalling or only slightly shorter than the second pinna pair. There is great variation in all these characters when specimens from throughout the range of D. patula are examined, and we are unable to separate the two satisfactorily. One of the collections cited as D. simplicior by Mickel and Beitel (1988) has irregularly shaped malformed spores (Mickel 6093, NY). A collection from Zacuapan, Veracruz (Purpus 3007, UC, US), with scales persistent along stipes and onto proximal part of the rachis, was annotated by Fraser-Jenkins, “. . . a distinct species . . . related to D. patula, but more dissected and more glandular on axes below. Seems to compare with var. serrata and chaerophylloides, but I am looking into its correct name-15 Nov 92.” Purpus 7868 (US) and Purpus 7879 (UC), also from Zacuapan, are similar but larger versions of this entity. Until the Dryopteris patula complex can be studied cytologically and isozymically, it seems premature to describe this variant. The sole collection from Tamaulipas is extremely aberrant in having very narrow, almost hair-like, reddish brown rhizome and stipe base scales (to ca. 10 x 0.3-0.5 mm) and small fronds (ca. 25 cm) and blades (16 x 6.5 cm), with pinnae to 4 x 2 cm; the blades are eglandular or nearly so on both sides, and the indusia are reddish brown. In some respects, it resembles certain specimens from Jamaica, e.g., Jenman s.n. (NY). It may represent an undescribed species in the Dryopteris patula complex, but more material and further study are needed before further subdivision of this species can be attempted. Perhaps the most aberrant element that we include in D. patula is a specimen from Chiapas, Breedlove 53929 (CAS), from a sandstone outcrop at Escopetazo (Mpio. Ixtapa). It has broadly deltate blades as broad as or slightly broader than long. Clearly it belongs in D. patula s.l., rather than being assignable to one of the other species with deltate blades (e.g., D. nubigena, D. futura, D. rossii).

     

     

  • Distribution

    Terrestrial (rarely epiphytic on old logs) in montane rain forests, seasonal forests, pine-oak forests; (200–)1300– 2500 m. Mexico; Guat, Hond, Salv, Nic, CR, Pan; Jam, Hisp; Col, Ven, Ec, Galapagos, Peru, Braz, Bol, nw Arg. Moran (in Davidse et al., 1995) also included Paraguay in the range.

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