Megalastrum macrotheca (Fée) A.R.Sm. & R.C.Moran

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum macrotheca (Fée) A.R.Sm. & R.C.Moran

  • Primary Citation

    Amer. Fern J. 77(4): 128. 1987

  • Basionym

    Phegopteris macrotheca Fée

  • Description

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

    Lectotype : (designated here): Guadeloupe. In 1864, F. L'Herminier s.n. (P-00600368; duplicates: P-00610561, RB, fragm. BM ex P).

    Description: Leaves up to 1.0 m long; scales of the petiole bases 0.7-1.0 × 0.1-0.2 cm, lanceolate, sparsely denticulate, brown; laminae up to 0.8 m long, 2-pinnate-pinnatifid at base, 1-pinnate-pinnatisect medially; basal pinnae 10-20 cm long, inequilateral; pinnules broadly adnate to the pinna rachis, 3-6 cm long; pinna rachises abaxially non-glandular, densely pubescent, scaly, the hairs ca. 0.4-0.6 mm long, 3- or 4-celled, spreading, the scales 3-5 mm long, lanceolate, brown, entire to sparsely denticulate, non-bullate, rachises adaxially non-glandular, lacking scales, densely pubescent, hairs 1.0-1.2 mm long, 5-8-celled; costules on the abaxial surface eglandular, puberulent and scaly, the hairs 0.2-0.4 mm long, 2- or 3-celled, acicular, erect to spreading, the scales like those on the pinna rachises abaxially but smaller, 2-2.5 mm long, the adaxial surface sparsely pubescent, the hairs 0.4-0.5 mm long, substrigose; laminar tissue between veins glabrous on both surfaces; veins visible on both surfaces, abaxially non-glandular, very sparsely pubescent, non-scaly, the hairs ca. 0.2 mm long, 1- or 2-celled, the scales ca. 0.3 mm long, uniseriate, appressed, reddish, adaxially non-glandular, glabrous; laminar margins sparsely ciliate, non-glandular, the hairs 0.3-0.4 mm long, 1-3-celled, spreading to ascending; indusia absent.

    Distribution and ecology: Haiti, Guadeloupe, Costa Rica, Panama, Colombia, Ecuador, Peru, Bolivia; wet forests, shady ravines, 900-2100 m.

    Comments: Megalastrum macrotheca has a distinctive laminar cutting characterized by pinnules that soon become broadly adnate to the pinna rachises. Its abaxially pubescent pinna rachises and entire to sparsely denticulate scales will distinguish it from many other species in the Antilles. The West Indian specimens appear identical to those from the Costa Rica, Panama, and the Andes. The syntype of Polypodium mazei at K consists of one sheet with two specimens with the collection number written on the label as "nos. 643, 786". It is thus impossible to select a lectotype. Duplicates of these collections were found at NY, P, and S (each with a single number, isosyntypes).

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