Diplazium striatum (L.) C.Presl

  • Authority

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

  • Family

    Athyriaceae

  • Scientific Name

    Diplazium striatum (L.) C.Presl

  • Description

    Species Description - Rhizomes erect; rhizome scales dark brown, lustrous, somewhat retiform, linear-lanceolate, 10-15 x 2-3 mm, cell walls sinuous; fronds 100-160 cm long; stipes dark brown at bases, stramineousdistally, 30-65 cm x 5-9 mm, 1/2-3/5 the frond length, with abundant, minute, erect, pale hairs ca. 0.1 mm long in the adaxial grooves; blades herbaceous, pinnate-pinnatifid proximally, or sometimes barely 2-pinnate, 35-100 x 25-50 cm, apices pinnatifid, buds absent; rachises glabrescent or moderately hairy; pinnae stalked 2-7 mm, equilateral, ca. 15-22 pairs per blade, 7-30 x 3-9 cm, oblong-lanceolate, proximal several pinna pairs sometimes with a few free or nearly free pinnules at bases, oblonglanceolate, cut usually 3/5-4/5(-9/10) the way to the costae, bases truncate, apices acuminate, pinnules or lobes 1.5-4 x 0.7-1.5 cm, slightly larger on sterile fronds, ca. 12-18 pairs per pinna, 1 or 2 proximal ones shortened, largest proximal ones broadly to narrowly adnate, distal ones broadly adnate and usually confluent, the largest pinnules lobed to 1/3 their width at their bases, otherwise merely crenate, spreading, obtuse at the tips; veins free, pinnate, 8-12 pairs per lobe, 1(-2)-forked; indument adaxially of abundant hairs in rachial and costal grooves, abaxially with a few scales on rachises and costae, also with hairs especially abundant on costae and costules but scattered to often dense between veins as well, hairs erect, 0.1-0.3 mm long, the longest ones septate; sori pinnate, 3-8 pairs per segment, with subentire indusia 2-8 x 0.3-0.6 mm; 2n= 328 (Jam).

  • Discussion

    Asplenium striatum L., Sp. Pl. 2: 1082. 1753. Type. Petiver, Pter. Amer., t. 3, f. 3, 4. 1712, which was based on Plumier, Traite´ Foug. Ame´r., pl. 18, 19, 1705, based on a collection from Martinique.

    Diplazium crenulatum Liebm., Mexic. Bregn. 254 (reprint 102). 1849. Lectotype (first chosen by Lellinger, Proc. Biol. Soc. Wash. 89: 710, 1977; rechosen by Mickel & Beitel, 1988: 158, a choice accepted here). Mexico. Veracruz: between Colipa and Misantla, Liebmann s.n. [Pl. Mex. 2383, Fl. Mex. 360] (C!, photo US!; isolectotypes K! frag. NY!). An unnumbered Liebmann specimen at US, from “between Colipa and Misantla,” was chosen as lectotype by Lellinger, but this specimen probably represents D. striatastrum; however, the proximal part of the blade, which might prove definitive, is absent. One of the syntypes in Copenhagen (Liebmann s.n. [Pl. Mex.] 2665, C, photos MO!, NY!) is also D. striatastrum and may be from the same gathering as Lellinger’s choice of lectotype.

    Diplazium elongatum Fe´e, Me´m. Foug. 5: 215. 1852. Type. Mexico. Oaxaca: [Dto. Choapan] Petlapa, Galeotti 6471 (P! photos UC!, US!; isotypes BR!-4 sheets).

    Diplazium matudae C. D. Adams, Novon 2: 295, f. 7. 1992. Type. Mexico. Chiapas: Escuintla, near Col. Zintalapa, 160 m, Matuda 18164 (MEXU; isotypes DS!, MO!, US!).

    Unverified, Doubtful, or Mistaken Reports. Hgo (reported by Mickel & Beitel, 1988, and Palacios-Rios, 1992, but not verified). Qro (Rzedowski 43300, IEB, cited by Arregui´n et al., 2001, but this specimen is D. striatastrum). Diplazium striatum differs from D. urticifolium in having hairs on the laminae and rachises abaxially, minute hairs in the grooves of costae and rachises adaxially, and pinnae cut 3/4 or more of the distance to costae. Occasional specimens of D. striatum appear glabrous abaxially, e.g., Palacios-Rios 3324 (XAL). Diplazium striatastrum (q.v.), with laminar and rachis hairs like D. striatum, was segregated from D. striatum on the basis of several characters. In D. striatum, the proximal pinnae are fully pinnate at their bases with 1–2 free pinnules, whereas in D. striatastrum the proximal pinnae resemble the middle pinnae, being pinnatifid with adnate basal segments. The size differences given in the key also serve to separate the two species, but there is some overlap. More work is needed to determine the degree of relationship of D. striatastrum to D. striatum. It is tempting to speculate that D. striatum may have arisen following hybridization of D. striatastrum and D. expansum, because of its somewhat intermediate morphology. Diplazium matudae was compared to D. biolleyi Christ, from Costa Rica, by Adams (1992), but that species has ovate costal scales and fully 2-pinnate-pinnatifid blades. Diplazium biolleyi seems not closely related to D. striatum, but may be the same as D. marattiifolium Christ. We find no significant differences between type and paratype material of D. matudae and typical D. striatum.

  • Distribution

    Wet montane forests; 150-2000 m. Mexico; Guat, Bel, Hond, Salv, Nic, CR, Pan; Gr & L Ant; Col, Ven, Trin, Ec, Peru, s Braz, Bol.

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