Monographs Details: Fissidens dissitifolius Sull.
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Family:Fissidentaceae
Synonyms:Conomitrium dissitifolium (Sull.) Müll.Hal.
Description:Species Description - Plants usually sordid olive green, often encrusted with lime. Stems monomorphic, unbranched and branched, to 24 mm [2.4 cm] long x 2-4 mm wide; rhizoids basal and axillary, smooth brown; axillary hyaline nodules absent; epidermis and outer cortical cells bulging, smaller than inner cortical cells, all thin-walled, usually hyaline; axillary, stalked, multicellular, clavate gemmae often present; central strand present or absent. Leaves crispate when dry, usually distant, as many as 27 pairs, lanceolate to oblong-ligulate, acute to obtuse, often ending in a short unicellular apiculus, 1.2-3.0 mm long x 0.2-0.6 mm wide; margin entire, often crenulate-serrulate at apex, limbate on all laminae, limbidium usually ceasing several cells below leaf apex and often above distal end of dorsal lamina, limbidial cells bistratose; costa percurrent or ending as many as 17 cells below apex, bryoides type, often reduced in structure; dorsal lamina usually rounded proximally, not decurrent; vaginant laminae ± 1/2-2/3 leaf length, acute, equal; laminal cells distinct, eguttulate, thin-walled, shrinking greatly upon drying, smooth, sometimes ± bulging, variable in shape, quadrate to oblong, pentagonal and hexagonal, (13-) 18-29(-36) µm long x 9-16 (-22) µm wide, larger and oblong, 119 µm long x 29 µm wide, juxtacostally in proximal regions of vaginant laminae. Monoicous (rhizauto-icous); perigonia and perichaetia terminal on stems ± equal in length. Sporophytes 1-3 per perichaetium, orange; seta smooth, 3.5-5.5 mm long; theca exserted, erect, radially symmetric, 0.60.9 mm long, stomatose, exothecial cells quadrate to oblong, vertical walls thicker than horizontal walls; peristome scariosus type; operculum conic, long-rostrate 0.6-0.7 mm long, ± as long as theca. Spores not seen [smooth, 8-10 µm diam., according to Grout, 1943]. Calyptra cucullate, smooth, 0.60.7 mm long.

Discussion:Fissidens dissitifolius is closely related to F. flaccidus from which it is distinguished by its smaller, thin-walled laminal cells and limbidium that ends below the leaf apex. Leaves of F. dissitifolius tend to be mostly lanceolate, although in more robust plants they verge on being narrowly oblong. The species is the only one in subgenus Aloma that is tufa-forming.
Distribution:Toledo Belize Central America| Pernambuco Brazil South America| Barbados South America| Saint Croix Virgin Islands of the United States South America| Saint Ann Jamaica South America| Saint Mary Jamaica South America| Chiapas Mexico North America| Guerrero Mexico North America| Michoacán Mexico North America| Nuevo León Mexico North America| Querétaro Mexico North America| San Luis Potosí Mexico North America| Tabasco Mexico North America| Tamaulipas Mexico North America| Veracruz Mexico North America| Chiquimula Guatemala Central America| Cayo Belize Central America| Olancho Honduras Central America| Santa Bárbara Honduras Central America| La Libertad El Salvador Central America| Darién Panamá Central America| Panamá Panama Central America| Cienfuegos Cuba South America| Guantánamo Cuba South America| La Habana Cuba South America| Piñar del Río Cuba South America| Santiago de Cuba Cuba South America| Villa Clara Cuba South America| Portland Jamaica South America| Trelawny Jamaica South America| Nord Haiti South America| Nord-Ouest Haiti South America| Ouest Haiti South America| Sud Haiti South America| Distrito Nacional Dominican Republic South America| Pedernales Dominican Republic South America| Peravia Dominican Republic South America| Puerto Rico South America| Antioquia Colombia South America| Valle del Cauca Colombia South America| Aragua Venezuela South America| Lara Venezuela South America| Sucre Venezuela South America| Huánuco Peru South America| Paraná Brazil South America| São Paulo Brazil South America| Tarija Bolivia South America| Amambay Paraguay South America| Central Paraguay South America| Guairá Paraguay South America| Paraguarí Paraguay South America| Salta Argentina South America| Martinique South America| Saint Thomas Jamaica South America|