Monographs Details: Fissidens gardneri Mitt.
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Scientific Name:Fissidens gardneri Mitt.
Description:Species Description - Plants dull green. Stems monomorphic, unbranched and branched, minute, to 4 mm long x 1.5 mm wide; rhizoids basal, smooth, light brown; axillary hyaline nodules absent; epidermis and outer tier of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled, hyaline; central strand absent. Leaves crispate, somewhat inrolled from tips when dry, loosely imbricate, as many as 18 pairs, ± oblong, rounded, to 1.2 mm long x 0.3 mm wide, perichaetial leaves often longest; margin crenulate, limbate on proximal 2/3 or less of vaginant laminae of perichaetial and subtending 1-2 pairs of leaves, weak, sometimes lacking, limbidial cells unistratose; costa ceasing well below the leaf apex, often not extending much beyond distal end of vaginant laminae, distally often spurred and sometimes obscured by overlying chlorophyllose cells, bryoides type; dorsal lamina narrowed to insertion, not decurrent; vaginant laminae 2/3 leaf length, unequal, minor lamina narrowed distally, ending on or very near costa to rounded and free; laminal cells obscure, eguttulate, unistratose, firm-walled, pluripapillose, rounded-hexagonal, 68 µm long, in transverse section twice as deep as wide. Monoicous (gonioautoicous); perigonia gemmiform, axillary; perichaetia terminal on stems and branches. Sporophytes 1 per perichaetium, yellow, darkening with age; seta smooth, short, to 1.2 mm long; theca exserted, erect, radially symmetric, cylindric, to 0.8 mm long, stomatose, exothecial cells quadrate to oblong, vertical walls thicker than horizontal walls; peristome anomalous, teeth erect when wet, undivided or incompletely divided, papillose throughout. Spores smooth, 23-34 µm diam. Operculum and calyptra not seen.

Discussion:Synonyms from outside the area of this study (Pursell et al., 1993): Fissidens brevinervis Broth., Fissidens foutadjalloni Paris, and Fissidens microcladus Thwaites & Mitt, in Mitt.

This minute moss is distinguished by its oblong-rounded leaves, a costa that does not extend much beyond the distal end of the unequal vaginant laminae of which the minor lamina is distally narrowed to the costa or rounded and free, a limbidum restricted to the proximal parts of the vaginant laminae of perichaetial and subtending leaves, small, obscure, pluripapillose laminal cells, a cylindric theca, and an anomalous peristome of which the papillose teeth are undivided or incompletely divided. Fissidens gardneri is closest to F. pallidinervis, but in this species the vaginant laminae are more or less equal, the costa is longer, and the peristome is a typical scariosus type.
Distribution:San Luis Potosí Mexico North America| Guanacaste Costa Rica Central America| Lara Venezuela South America| Goiás Brazil South America| São Paulo Brazil South America|