Megalastrum lunense (Christ) A.R.Sm. & R.C.Moran

  • Family

    Dryopteridaceae (Pteridophyta)

  • Scientific Name

    Megalastrum lunense (Christ) A.R.Sm. & R.C.Moran

  • Primary Citation

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

  • Basionym

    Aspidium lunense Christ

  • Description

    by: R.C. Moran, J. Prado

    Lectotype: (designated here): Costa Rica. Cartago: Luna, [9°48'N 83°53'W], in 1905, C. Wercklé s.n. (P-00600390, P-00600389); duplicates: P-00600388, fragm. BM and U ex P).

    Description: Rhizomes erect; leaves up to 1.5 m long (estimate); scales of the petiole bases 10-15 × ca. 2.5 mm, ovate to lanceolate, slightly twisted, spreading to ascending, brown, shiny, denticulate on the margins; laminae up to 0.3-0.8 m long, 3-pinnate-pinnatisect, 2-pinnate-pinnatisect medially; basal pinnae ca. 0.2-0.4 m long, strongly inequilateral (elongated basiscopically); pinna rachises abaxially densely pilose, non-glandular (i.e., without capitate-glandular hairs or sessile spherical glands), scaly, the scales to ca. 2-3 × ca. 1.5 mm, ovate to lanceolate, flat (not twisted), flaccid, spreading, brown, shiny, entire or nearly so, brown, shiny, adaxially non-glandular, densely pilose, the hairs 1-1.3 mm long, 6-9-celled, spreading; costules on both surfaces with indument like the pinna rachises but with a few sessile and stalked glands; laminar tissue between the veins abaxially puberulent, the hairs 0.1-0.3 mm long, 3-celled, erect, acicular, the glands stalked, ca. 0.1-0.2 mm long, capitate, these mixed with sparse sessile sphearical glands, a few proscales present abaxially, adaxially with similar indument but sparser; veins visible on both surfaces, sparsely pubescent like the lamina tissue; hydathodes conspicuous; lamina margins ciliate, the hairs 0.2-0.3 mm long, 1-3-celled, erect, acicular, non-glandular; indusia absent.

    Distribution: Mexico, Belize, Guatemala, Nicaragua, Costa Rica, Panama; wet forests, 70-1600 m.

    Comments: Megalastrum lunense is characterized by petioles and pinna rachises with wide (up to 2.5 mm) ovate to lanceolate scales, pinna rachises and costules abaxially with hairs up to 1 mm long and 4-7-celled, abaxial surfaces of the laminae with glands varying from stalked to sessile. Megalastrum palmense differs by scales flaccid and appressed to the petioles and leaf axes, lack of glands (either stipitate or sessile), and by the minute (ca. 0.1 mm long) substrigose pubescence on the leaf axes abaxially. Megalastrum atrogriseum also has long hairs abaxially, and these can be mixed with sessile and stalked glands. It differs by its pinna rachis scales that are narrower (0.3-0.4 mm), firm (not twisted or tortuous), yellowish brown, and denticulate.

  • Floras and Monographs

    Megalastrum lunense (Christ) A.R.Sm. & R.C.Moran: [Article] Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.