Megalastrum abundans (Rosenst.) A.R.Sm. & R.C.Moran

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum abundans (Rosenst.) A.R.Sm. & R.C.Moran

  • Primary Citation

    Amer. Fern J. 77(4): 127. 1987

  • Basionym

    Dryopteris abundans Rosenst.

  • Description

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

    Lectotype: (designated by Moran et al, 2009): Brazil. Rio Grande do Sul: Mun. Santa Cruz, [29º43'S, 52º52'W], Sette Lagoas do Herval do Paredão, 2 Mar 1905, Jürgens 195 [Rosenstock Filices Austrobrasilienses no. 367] (NY; duplicates: B, NY, P, R-n.v., S-n.v.).

    Description: Leaves to 2.5 m long; scales of petiole bases 1-3 × 0.2-0.35 cm, linear, sparsely denticulate, brown; laminae 1-2 m long, 4-pinnate-pinnatifid at base, 3-pinnate-pinnatifid medially; proximal pinnae ca. 0.7 m long, strongly inequilateral, pinnules acroscopically reduced toward bases of pinnae; pinna rachises abaxially non-glandular, sparsely pubescent, hairs 0.5 mm, 4- or 5-celled, adaxially non-glandular, densely pubescent, hairs 0.3-0.4 mm long, 5- to 7-celled, scales 0.8-1.0 mm long, bullate, brown, ovate-lanceolate; costules on abaxial surfaces non-glandular, pubescent, hairs 0.1-0.5 mm, 1-4-celled, sparsely scaly, scales 0.8-1.0 mm long, bullate, brown, ovate-lanceolate; laminar tissue between veins abaxially non-glandular, glabrous to sparsely pubescent, hairs ca. 0.1 mm long, 2-celled, erect, adaxially glabrous (sparse hairs only on veins); veins visible on both surfaces, abaxially non-glandular, pubescent and minutely scaly, hairs 0.2-0.3 mm long, 1- or 2-celled, scales ca. 0.3 mm long, uniseriate, appressed, reddish, adaxially non-glandular, sparsely pubescent, hairs 0.3-0.5 mm long, 1-3-celled; lamina margins ciliate, hairs ca. 0.1 mm long, 1-celled, glandular hairs absent; indusia absent.

    Distribution: Endemic to coastal Brazil; 600-1200 m.

    Comments: Megalastrum abundans is characterized by bullate scales on the costae and costules abaxially, lamina tissue glabrous adaxially between veins, veins pubescent adaxially, and non-indusiate sori. It and M. crenulans are the most finely divided species in the area, with laminae 4-pinnate (or more) at their bases. Megalastrum abundans differs from M. crenulans by lack of indusia.

  • Sorry, no descriptions available for this record.