Selaginella oaxacana Spring

  • Authority

    Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.

  • Family

    Selaginellaceae

  • Scientific Name

    Selaginella oaxacana Spring

  • Description

    Species Description - Stems erect, base decumbent with age, to 90 cm tall, 2-3 mm diam., not articulate, not flagelliform, stoloniferous, stramineous to pale green; rhizophores restricted to base, to 1 mm diam.; leaves on main stem isomorphic, anisophyllous otherwise; leaves dark green on both sides, glabrous, with epidermal streaks (esp. visible on upper surface on lateral and median leaves), leaf margins often curling on drying; leaves on main stem below first branch appressed, ovate, rounded, apex acute, base rounded, margin finely denticulate; lateral leaves obliquely oblong, ca. 4-5 mm long on main stem, ca. 3 mm long on branches, 2 mm wide, apex obtuse, base truncate to rounded along lower margin, rounded along upper margin, lower margin minutely denticulate at base, entire to apex, upper margin minutely denticulate; median leaves ovate, acuminate, denticulate, oblique at base with subequal small auricles; axillary leaves ovate, exauriculate, base rounded to subcordate, minutely denticulate at base; strobili 2 mm wide (incl. leaf tips), 5-10 mm long; sporophylls monomorphic and of two colors (upper [median] two ranks green, lower [lateral] two ranks colorless), ascending, symmetric, with denticulate margin and slight keel; megasporangia in two ranks; megaspores cream-white, 260-420 µm diam., with low narrow ridges to nearly smooth; microspores orange-yellow, nearly smooth to short-papillate.

  • Discussion

    Type. Mexico. Oaxaca: Chinantla, Galeotti 6608 bis (LG?; =6608, P!, BR!, same no. as cited for S. martensii). Lycopodium flabellatum Linnaeus var. strictum Martens & Galeotti, Mém. foug. Mexique 12. 1842. Type. Mexico. Oaxaca: Galeotti 6608 (BR!; isotype P!; see above). This is the most common of the taller, caulescent Selaginellas in Oaxaca. In general aspect, S. oaxacana closely resembles S. mosorongensis and S. cuneata, but the former can be distinguished by its reflexed stem leaves with large, long-ciliate auricles, more ciliate, long-aristate median leaves with unequal auricles, ciliate axillary leaves and tan megaspores; the latter is distinct in its cuneate-based lateral and axillary leaves, and relative lack of epidermal streaks. Selaginella wendtii has stem, lateral, median and axillary leaves ciliate at their bases.

  • Distribution

    Terrestrial in montane rain forest of Atlantic slope; Choapan, Cuicatlán, Ixtlán, Juchitán, Tehuantepec, Teotitlán, Tuxtepec, Villa Alta; 250-1500 m. Mexico (Ver, Oax, Chis); Guat to Pan; Col.

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