Megalastrum organense R.C.Moran, J.Prado & Labiak

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum organense R.C.Moran, J.Prado & Labiak

  • Primary Citation

    Amer. Fern J. 99: 24,25 & 29, Figs. 3D, 7E,. 2009

  • Type Specimens

    Specimen 1: Isotype -- P. H. Labiak E. 4485

    Specimen 2: Isotype -- P. H. Labiak E. 4485

    Specimen 3: Isotype -- P. H. Labiak E. 4485

  • Description

    by: R.C. Moran, J. Prado, and P.H. Labiak

    Type: Brazil. Rio de Janeiro: Mun. Teresópolis, Parque Nacional da Serra dos Órgãos, Floresta Atlântica, 22°26'56"S, 42°59'06"W, 1700 m, 13 Jan 2008, Labiak et al. 4485 (holotype: UPCB; isotypes: NY, SP)

    Description: Leaves to 1.5 m long; scales of the petiole bases ca. 1.5 × 0.15 cm, narrowly lanceolate, retrorsely denticulate, brown, flat (not twisted), en masse not forming a woolly tuft; laminae to 1 m long, to 3-pinnate-pinnatifid at base, 2-pinnate-pinnatisect medially, dull on both surfaces, paler abaxially; basal pinnae 35-45 cm long, stalks to 1.5 cm long, inequilateral, pinnules acroscopically slightly reduced toward the pinna bases; pinna rachises abaxially non-glandular, pubescent to glabrescent, scaly, hairs 0.2-0.3 mm long, 3- or 4-celled, patent, scales ca. 3-7 mm long, narrowly lanceolate to linear, brown, retrorsely denticulate, flat (not bullate), adaxially non-glandular, pubescent, hairs ca. 0.5 mm long, 3-5-celled, spreading to antrorsely strigose; costules abaxially non-glandular, puberulent, hairs ca. 0.2-0.3 mm long, 3-celled, scaly, scales like those of pinna rachises but smaller and lanceolate, entire to retrorsely denticulate so, shiny and brown, loosely appressed, ca. 3 mm long, adaxially puberulent, hairs ca. 0.1 mm long, 2- or 3-celled, spreading; laminar tissue between veins abaxially non-glandular, glabrous with some inconspicuous, uniseriate, appressed, reddish scales, adaxially glabrous; veins visible on both surfaces, non-glandular, abaxially glabrous or sparsely pubescent, hairs ca. 0.1-0.2 mm long, 1- or 2-celled, adaxially pubescent, hairs ca. 0.3-0.5 mm long, 1-3-celled, spreading to antrorsely strigose; lamina margins sparsely ciliate, hairs ca. 0.1-0.2 mm long, 2-celled, spreading to appressed; indusia absent.

    Distribution: Endemic to Rio de Janeiro, Brazil; 1500-1750 m.

    Comments: Megalastrum organense is named for the Organ Mountains of Rio de Janeiro. Like M. retrorsum, it has retrorsely denticulate scales. See comments under that species for comparison.

  • Sorry, no descriptions available for this record.