Pecluma dispersa (A.M.Evans) M.G.Price

  • Authority

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

  • Family

    Polypodiaceae

  • Scientific Name

    Pecluma dispersa (A.M.Evans) M.G.Price

  • Description

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    Species Description - Rhizomes short-creeping, 4–8 mm diam.; rhizome scales reddish brown, lustrous, 2–4 x 0.3–1(–1.5) mm, lanceolate, acuminate, entire; fronds 27–63 cm long, clumped; stipes black, 1/7– 2/7 the frond length, adaxial surfaces densely pilose with acicular hairs 0.1 mm and scattered, appressed ctenoid hairs; blades narrowly deltate, 5–10 cm wide, reduced to lobes; pinnae somewhat deflexed proximally, the largest 2.5–5 cm x 2–5 mm, obtuse, equilateral at bases, surcurrent and decurrent, costae of proximal pinnae decurrent onto rachises; rachises abaxially with dark reddish brown, lustrous, ovate to narrowly deltate, acuminate scales; veins free, 1–2-forked; indument adaxially of numerous hairs 0.1– 0.3 mm on costae, laminar surfaces with scattered hairs to ca. 0.5 mm, abaxially the costae with scattered septate hairs to 0.5 mm, surfaces between veins with appressed hairs 0.1–0.2 mm, margins with scattered to numerous hairs 0.3–0.5 mm; sori round (to oblong), medial, with a few clavate paraphyses 0.5– 0.8 mm; sporangia glabrous or often with several inconspicuous hairs ca. 0.1 mm; spores globose, 32 per sporangium; 2n =111, apogamous (Fla, Jam).

  • Discussion

    Polypodium dispersum A. M. Evans, Amer. Fern J. 58: 173, t. 27. 1968. Type. U.S.A. Florida: Citrus Co., Pineola Grottoes, Evans 2008 (MICH!; isotypes NY!, TENN, US!).

    Among the black-stiped species of Pecluma, P. dispersa is distinct in its densely puberulent stipes and rachises adaxially, lanceolate, denticulate rhizome scales, and 32 globose spores per sporangium. It is similar to P. atra in having numerous deltate to lanceolate scales on the rachises abaxially, and these scales sometimes extend to the proximal portions of the costae. There are scattered septate hairs on the laminae adaxially, but usually fewer and more concentrated toward the pinna margins compared to P. atra (but see Reeves 6134, which equals P. atra in hairiness adaxially). On morphological and cytological grounds, Evans (1968) postulated that P. dispersa was the hybrid between P. atra, a diploid, and P. plumula, a tetraploid. It reproduces successfully by an apogamous life cycle, well documented by Evans.

  • Distribution

    Epipetric or in rock crevices (or epiphytic or terrestrial), pine-oak forests; 0-1700 m. USA (Fla), Mexico; Guat, Bel, Hond, Nic (Grijalva & Burgos 1545, UC); Gr Ant; Col, Ven, Ec, Galapagos, Braz, Bol.

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