Nephrolepis biserrata (Sw.) Schott

  • Authority

    Mickel, John T. & Smith, Alan R. 2004. The pteridophytes of Mexico. Mem. New York Bot. Gard. 88: 1-1054.

  • Family

    Nephrolepidaceae

  • Scientific Name

    Nephrolepis biserrata (Sw.) Schott

  • Description

    Species Description - Rhizomes suberect to erect, stout, lacking tubers; rhizome scales concolorous, pale brown to orange, lanceolate, 5–7 mm long; stipes light brown, 20–30 cm long, filiform-scaly to glabrescent; blades firm-herbaceous, linear-elliptic, 75–100(–200) x (11–)16–24 cm; rachises stramineous to tan, with dense, fibrillose scales, 1–2 mm long, adaxial surfaces with catenate hairs; pinnae short-stalked, ± equally cuneate to equally auriculate at bases, (5–)8.5–20 x 0.9–2 cm, apices of longest pinnae acuminate, margins finely serrulate (sterile blades) to crenulate or bicrenulate (fertile blades); indument abaxially, especially on costae, of fine, often rather dense catenate hairs 0.2–0.6 mm long and scattered to dense, tan, fibrillose scales, especially on costae, adaxial surfaces with numerous catenate hairs 0.1–0.3 mm long on costae; hydathodes often lime-dotted on adaxial blade surfaces; indusia brown, round-reniform, 0.8–1 mm diam., with a few hairs 0.1–0.3 mm long, each indusium with a narrow sinus (mature sporangia projecting on all sides); 2n = 82 (Jam, PR, Trin, Africa, India).

  • Discussion

    Aspidium biserratum Sw., J. Bot. (Schrader) 1800(2): 32. 1801. Type. Mauritius. Gro¨ndal s.n. (S). Nephrolepis mollis Rosenst., Repert. Spec. Nov. Regni Veg. 22: 13. 1925. Type. Costa Rica. Brade 141 [Rosenst. exs. 289] (S?; isotypes NY!, UC!).

    Unverified, Doubtful, or Mistaken Reports. Jal (Marti´nez s.n., May 1989, IBUG, cited by Mickel, 1992, but not verified). Yuc (Tun G. 262, UADY, cited by Palacios-Rios, 2002b, but not verified). The rotund-reniform indusia with occasional hairs, pinnae with hairs on the costae adaxially and laminar tissue abaxially, and concolorous, spreading rhizome and stipe base scales distinguish this species. See key for comparison with N. hirsutula, seemingly a recent introduction. In Florida and Jamaica N. biserrata hybridizes with N. exaltata to produce an abortive-spored hybrid (N. x averyi), described by Nauman (Amer. Fern J. 69: 69. 1979). The hybrid grows with its two parents, is larger than N. exaltata, and has sparse hairs adaxially. Paleotropical material under this name in herbaria, when not misidentified (which is often the case), seems to diverge significantly in a number of characters, including pubescence and pinna shape. Most likely, the name, as currently applied, encompasses more than one species, but a better delimitation of species in this presumed complex must await more critical examination of specimens throughout the range.

  • Distribution

    Terrestrial, epipetric or epiphytic on matorral, palm plantations (Tabasco), evergreen rain forests; 100–1000 m. USA (Fla); Mexico; Guat, Bel, Hond, Salv, Nic, CR, Pan; Bah, Gr & L Ant; Col, Ven, Trin, Guy, Sur, Fr Gui, Ec, Peru, Braz, Bol; Africa, Asia, Polynesia.

    Oceania| Asia| Africa| Bolivia South America| Brazil South America| Peru South America| Ecuador South America| French Guiana South America| Suriname South America| Guyana South America| Trinidad and Tobago South America| Venezuela South America| West Indies| Bahamas South America| Panama Central America| Costa Rica South America| Nicaragua Central America| El Salvador Central America| Honduras Central America| Belize Central America| Guatemala Central America| México Mexico North America|