Megalastrum wacketii (Rosenst. ex C.Chr.) A.R.Sm. & R.C.Moran

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum wacketii (Rosenst. ex C.Chr.) A.R.Sm. & R.C.Moran

  • Primary Citation

    Amer. Fern J. 77(4): 129. 1987

  • Description

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

    Type: Brazil. São Paulo: Pilar, Wacket 223 (holotype: BM).

    Description: Leaves to 1.5 m long [estimate]; scales of the petiole bases ca. 2 × 0.3-0.35 cm, narrowly lanceolate to linear, sparsely denticulate, brown, flat (not twisted), en masse not forming a woolly tuft; laminae 1 m long [our estimate], to 3-pinnate-pinnatisect at base, 2-pinnate-pinnatifid medially; basal pinnae to 35 cm long, stalks to 1 cm long, strongly inequilateral, pinnules acroscopically slightly reduced toward pinna bases; pinna rachises abaxially non-glandular, moderately to densely pubescent, very sparsely scaly, hairs 0.3-1.0 mm long, 2-7-celled, scales 0.5-1 mm long, narrowly lanceolate to linear, brown, entire to sparsely denticulate, flat (not bullate) adaxially non-glandular, densely pubescent, hairs ca. 1 mm long, 5- or 6-celled, patent, not strigose; costules abaxially non-glandular, pubescent, hairs generally of two lengths, long ones ca. 0.8-1.0 mm long, 4- or 5-celled, and shorter ones ca. 0.2 mm long, 1- or 2-celled, scaly, scales like those of pinna rachises, adaxially non-glandular, pubescent, hairs of two sizes, longer ones ca. 1 mm, 3- or 4-celled, and shorter ones ca. 0.3 mm, 1- or 2-celled; laminar tissue between veins abaxially glandular, densely pubescent, and sparsely scaly, glands 0.1-0.2 mm long, 2-celled, erect, capitate, hairs ca. 0.2 mm long, 1-celled, erect, scales ca. 0.3 mm long, uniseriate, linear, appressed, reddish, inconspicuous, adaxially sparsely pubescent, hairs 0.2-0.3 mm long, 1- or 2-celled, spreading, sparsely scaly, scales ca. 0.2-0.4 mm long, uniseriate, appressed, light reddish, surfaces shiny and darker than abaxial surfaces; veins visible on both surfaces, non-glandular, pubescent and scaly, hairs of two sizes, longer ones ca. 0.6 mm, 1-3-celled, and shorter ones ca. 0.2 mm, 1- or 2-celled, adaxially densely pubescent, hairs 0.6-0.7 mm long, 3-4(-5) celled, smaller ones ca. 0.2 mm long, 1- or 2-celled; lamina margins ciliate, non-glandular, hairs ca. 0.3 mm long, 1- or 2-celled; indusia absent.

    Distribution: SE Brazil (Espírito Santo and São Paulo; 500-1000 m.

    Comments: Megalastrum wacketii has laminae that dry dark greenish or blackish. The short, capitate-glandular hairs are distinctive on the laminar surfaces abaxially. It most resembles M. abundans by the division of the laminae and the short (ca. 0.1 mm long) hairs on the laminar surfaces between the veins, but the latter species lacks glandular hairs on the abaxial surfaces of the laminae and has conspicuous bullate scales on the costae abaxially.

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