Fissidens dubius P.Beauv.

  • Authority

    Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)

  • Family

    Fissidentaceae

  • Scientific Name

    Fissidens dubius P.Beauv.

  • Type

    Type. U.S.A. Without locality and collector (lectotype, GL-Amott, designated by Karttunen, 1987, not seen; isolectotypes, FH, H-SOL).

  • Synonyms

    Skitophyllum adianthoides var. marginatum P.Beauv. ex Bach.Pyl., Fissidens adianthoides var. marginatus (Bach.Pyl.) Brid., Fissidens cristatus Wilson & Mitt., Fissidens circinans Müll.Hal.

  • Description

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    Species Description - Plants usually dark green. Stems monomorphic, to 25 mm [2.5 cm] long x 3.5 mm wide, unbranched and branched; rhizoids basal, smooth, reddish; axillary hyaline nodules absent; epidermis and outer 1-3 tiers of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled, hyaline; central strand present. Leaves ± inrolled from tips, ± crispate when dry, imbricate, as many as 25 pairs, lanceolate to oblong, often undulate, obtuse to acute, often apiculate, to 3.5 mm long x 0.7 mm wide; margin crenulate to crenulate-serrulate, unevenly serrate distally, elimbate; costa distinct, ending a few cells below leaf apex to percurrent, taxifolius type; dorsal lamina truncate to rounded at insertion, not decurrent; vaginant laminae of cauline leaves ± 2/3 leaf length, acute, slightly unequal, minor lamina ending near margin; laminal cells ± obscure, eguttulate, irregularly bistratose in dorsal and ventral laminae, firm-walled, smooth, bulging, rounded-hexagonal, 7-10 µm long, 3-4 rows of marginal cells thinner, with slightly thicker walls, forming a pale band. Monoicous (rhizautoicous) or dioicous (?); perigo-nia terminal on short axillary branches or on longer stems; perichaetia terminal on short axillary branches near proximal end of stem. Sporophytes 1 per perichaetium, reddish; seta smooth, to 11 mm [1.1 cm] long; theca exserted, ± inclined, ± arcuate, bilaterally symmetric, to 1.8 mm long, stomatose, exothecial cells quadrate to oblong, vertical walls thicker than horizontal walls; peristome taxifolius type; operculum conic, long-rostrate, 1-1.4 mm long. Spores finely papillose, 13-20 µm diam. Calyptra cucullate, smooth, to 1.8 mm long. n = 8, 12, 13, 16 (as Fissidens cristatus; Fritsch, 1991).

  • Discussion

    Synonyms from outside the area of this study (Grout, 1943; Iwatsuki & Suzuki, 1982; Karttunen, 1987; and, Norkett in Gangulee, 1971): Fissidens adianthoides var. polyphylloides Besch., Fissidens adianthoides var. savatieri Besch., Fissidens adianthoides var. savatieri fo. atrovirens Besch., Fissidens adianthoides var. savatieri fo. cyathicarpus Besch., Fissidens adianthoides var. savatieri fo. praecox Besch., Fissidens adianthoides var. savatieri fo. subdecipiens Besch., Fissidens atrovirens Cardot in Dixon & P. de la Varde, Fissidens collinus Mitt., Fissidens decipiens DeNot. in Picc., Fissidens erosodentatus Cardot, Fissidens floridanus Lesq. & James, Fissidens koshikijimensis Sakurai, Fissidens micro-japonicus Paris, Fissidens obsoleto-marginatus Miill. Hal., Fissidens pseudo-gymnogynus Toyama, and Fissidens rupestris Wilson in Mackinlay.

    Fissidens dubius is distinguished by its irregularly serrate leaf margin, irregularly bistratose, somewhat obscure lamina cells, and sporophytes terminal on short axillary branches in the proximal parts of stems. Fissidens bourgaeanus, a species with which it can be confused, also has irregularly bistratose laminal cells, and often an irregularly serrate leaf margins. However, the plants of this latter species are larger than F. dubius and the marginal cells are thick, forming a dark marginal band. Iwatsuki and Suzuki (1982) reported that Japanese plants of F. dubius are phyllodioicous (pseudautoicous).

  • Distribution

    Mexico (Chiapas, Sonora, Tamaulipas, Veracruz); Central America (Costa Rica, Guatemala, Honduras); West Indies (Dominican Republic, Haiti, Jamaica); on moist soil, rocks (including limestone), boulders, exposed roots, rotted wood, and tree trunks; 1080-2700 m. The species is widely distributed in the Northern Hemisphere.

    Chiapas Mexico North America| Sonora Mexico North America| Tamaulipas Mexico North America| Veracruz Mexico North America| Alta Verapaz Guatemala Central America| Comayagua Honduras Central America| Puntarenas Costa Rica Central America| Portland Jamaica South America| Ouest Haiti South America| Independencia Dominican Republic South America| La Vega Dominican Republic South America| Pedernales Dominican Republic South America| Santiago Dominican Republic South America|