Megalastrum umbrinum (C.Chr.) A.R.Sm. & R.C.Moran

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum umbrinum (C.Chr.) A.R.Sm. & R.C.Moran

  • Primary Citation

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

  • Basionym

    Dryopteris umbrina C.Chr.

  • Description

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

    Lectotype: (designated by Moran et al, 2009): Brazil. São Paulo: Cantareira [ca. 23º20'S, 46º41'W], Jun 1913, Brade 6532 (NY-00149429; duplicates: BM-n.v., R-n.v.; photo MICH ex BM).

    Description: Leaves to 1.5 m long; scales of the petiole bases 1.5-2 × 0.07-0.1 cm, linear, sparsely denticulate (nearly entire), brown; laminae ca. 1 m long, 3-pinnate-pinnatisect at base, 2-pinnate-pinnatisect medially; basal pinnae ca. 30 cm long, strongly inequilateral, pinnules acroscopically reduced toward pinna bases; pinna rachises abaxially glandular, pubescent, scaly, glands ca. 0.05 mm long, sessile, yellowish, hairs of two sizes, from 0.1 to 0.4 mm long, 2-6-celled, acicular, scales to 3.5 mm long, lanceolate, non-bullate, entire to subentire, brown, spreading, adaxially inconspicuously glandular, pubescent, glands like those abaxially, hairs 0.4-0.7 mm long, 2- to 5-celled; costules abaxially with indument like that of the pinna rachises, adaxially pubescent, not scaly, hairs 0.4-0.7 mm long, 2-5-celled, erect; laminar tissue between veins abaxially sparsely glandular, not scaly, hairs ca. 0.1-0.2 mm long, 1- or 2-celled, erect to (rarely) appressed, inconspicuous, adaxially glabrous or rarely with a few hairs near margins; veins visible on both surfaces, pubescent on both surfaces, abaxially hairs 0.2-0.3 mm long, 1- or 2-celled, adaxially the hairs denser, 0.1-0.5 mm long, 2-5-celled, spreading to appressed; lamina margins ciliate, non-glandular, hairs 0.2-0.3 mm long, 2- or 3-celled, appressed; indusia absent.

    Distribution: Southeastern Brazil, Paraguay; 100-1200 m.

    Comments: Megalastrum umbrinum is distinctive by small but conspicuous, spreading scales along the rachises and pinna rachises-a characteristic that will help distinguish this species from many others in Brazil. Also helpful are the abaxial surfaces of the axes that are densely puberulent with short glandular hairs, and acicular (non-glandular) hairs of mixed sizes. The most similar species is Megalastrum adenopteris, which differs by the adaxial surfaces between the veins densely and evenly pubescent. It also has minute fugacious indusia.

  • Sorry, no descriptions available for this record.