Selaginella silvestris Aspl.

  • Authority

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

  • Family

    Selaginellaceae

  • Scientific Name

    Selaginella silvestris Aspl.

  • Description

    Species Description - Stems suberect to trailing, stramineous, ca. 0.8–1.5 mm diam., articulate, not flagelliform, not stoloniferous, stramineous, 2–3 times branched; rhizophores borne throughout stem length, ca. 0.5 mm diam., leaves of two kinds (anisophyllous) throughout stem length; lateral leaves obliquely oblong, to 3.5 mm long, bases truncate, rounded acroscopically, margins denticulate proximally, entire distally, apices obtuse; median leaves ovatelanceolate ovatelanceolate, bases with subequal auricles, margins minutely denticulate, apices long-acuminate to aristate; axillary leaves obovate-lanceolate, exauriculate, margins denticulate at bases and tips; strobili quadrangular, 5–15 mm long, with megasporophylls as large as lateral leaves, microsporophylls as small as median leaves; megasporangia single, at base of strobili; microsporangia in most strobili; megaspores cream to beige, reticulate; microspores beige to pale orange, spinulose.

  • Discussion

    Type. Bolivia. Sur Yungas: Ad El Chaco, Asplund 1140 (S).

    The denticulate lateral and axillary leaves, both lacking auricles, and denticulate median leaves with small, subequal auricles distinguish S. silvestris from the two other articulate species (S. stellata and S. tarda) with non-peltate median leaves. Selaginella stellata has ciliate lateral and axillary leaves, both with auricles, and ciliate median leaves with one auricle larger than the other; S. tarda has median leaves with one large auricle. The other articulate species in Mexico, S. schizobasis, S. eurynota, and S. sertata, all have peltate median leaves. Most specimens in Mexico are from higher elevations than other articulate species (1700–2800 m). Two collections from Oaxaca (100 m, Mickel 6828, NY; 20 m, Marti´nez-C. 332, NY, UC, US) are from low elevations and appear similar to S. silvestris in most respects. However, they have peculiar branches, especially near the plant base, which lack lateral leaves, thus appearing flagelliform. It is not clear whether this is a genetic feature or the action of an herbivore.

  • Distribution

    Terrestrial in wet montane forests and cloud forests; (0–)1700–2800 m. Mexico; Guat, Bel, Hond, Salv, Nic, CR; Col, Ven, Ec, Peru, Bol.

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