Monographs Details: Fissidens scariosus Mitt.
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Synonyms:Conomitrium assimile Hampe, Fissidens assimilis (Hampe) Paris, Conomitrium goebelii Müll.Hal., Fissidens goebelii Müll.Hal., Fissidens subprosenchymaticus Paris, Conomitrium commutatum Müll.Hal., Fissidens commutatus (Müll.Hal.) Broth., Conomitrium generalium Müll.Hal., Fissidens generalium (Müll.Hal.) Broth., Conomitrium prosenchymaticum Müll.Hal., Fissidens parenchymaticus Paris, Fissidens pseudoflabellatus Besch. & Geh.
Description:Species Description - Plants bright to olive green or brownish. Stems monomorphic, unbranched, 1.7-7 mm long x 1.4-2.5 mm wide; rhizoids basal, smooth, light brown; axillary hyaline nodules absent; epidermis and outer 12 tiers of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled, hyaline; central strand present. Leaves little changed when dry, loosely imbricate, as many as 10 pairs, lanceolate to oblong-lanceolate, acute to short-acuminate, to 2.8 mm long x 0.5 mm wide; margin ± entire, limbate on all laminae, limbidium weak, most noticeable in older plants, limbidial cells unistratose; costa usually ending well below apex, but extending beyond the vaginant laminae, sometimes forked distally, reduced bryoides type; dorsal lamina narrowed proximally, usually reaching insertion; vaginant laminae 1/2-2/3 leaf length, acute, unequal, minor lamina ending ± half way between costa and margin or closer to margin; laminal cells distinct, egutullate, unistratose, firm-walled, smooth, prosenchymatous, 90-128 µm long x 9-27 µm wide. Monoicous (rhizautoicous); perigonial terminal on stems shorter than perichaetial stems; perichaetia terminal on stems. Sporophytes 1 per perichaetium, yellow, darkening with age; seta smooth, 4-11.5 mm long; theca exserted, erect, radially symmetric, ovoid to ± cylindric, 0.45-1.0 mm long, stomatose, exothecial cells ± quadrate, vertical walls thicker than horizontal walls, collenchymatous; peristome scariosus type; operculum conic, long-rostrate, 0.5-0.6 mm long. Spores smooth, 7-13 pm diam. Calyptra cucullate, smooth, 0.6 mm long.

Discussion:This handsome species is distinguished by its glossy appearance, prosenchymatous laminal cells, short costa, weak limbidium, and unequal vaginant laminae. The laminal cell walls are firm so that there is little shrinkage of the leaves when dry. The weak limbidium, composed of cells that are narrower than the interior laminal cells, can often go unnoticed and is best seen in older plants. Fissidens scariosus can be confused with F. amazonicus, another species with prosenchymatous laminal cells, but the plants of the latter species are usually larger and laxer, with equal vaginant laminae, wider laminal cells, and a costa that does not extend beyond the distal ends of the vaginant laminae.
Distribution:Amazonas Colombia South America| Vaupés Colombia South America| Napo Ecuador South America| Pastaza Ecuador South America| Saint-Laurent-du-Maroni French Guiana South America| Wanica Suriname South America| Veracruz Mexico North America| Toledo Belize Central America| Comayagua Honduras Central America| Darién Panamá Central America| Caquetá Colombia South America| Santander Colombia South America| Distrito Federal Venezuela South America| Brokopondo Suriname South America| Para Suriname South America| Paramaribo Suriname South America| Sipaliwini Suriname South America| Morona-Santiago Ecuador South America| Peru South America| Amazonas Brazil South America| Minas Gerais Brazil South America| Pará Brazil South America| Paraná Brazil South America| Pernambuco Brazil South America| Rio de Janeiro Brazil South America| Rondônia Brazil South America| Santa Catarina Brazil South America| São Paulo Brazil South America| Cochabamba Bolivia South America| Santa Cruz Bolivia South America|