Monographs Details: Fissidens hornschuchii Mont.
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Synonyms:Conomitrium hornschuchii (Mont.) Hampe, Fissidens brasiliensis Hornsch., Fissidens martianus Hampe, Conomitrium glaziovii Hampe, Fissidens glaziovii (Hampe) Paris, Conomitrium glaziovii var. minor Hampe, Conomitrium polycarpum Besch., Fissidens polycarpus Hedw., Fissidens guarani W.R.Buck, Fissidens longipedicellatus Müll.Hal., Fissidens evanescens Broth., Fissidens constrictus Müll.Hal., Fissidens calochlorus Broth., Fissidens brevifalcatus Müll.Hal., Fissidens paucifolius Besch., Fissidens saltograndensis Broth., Fissidens legalloi H.A.Crum
Description:Species Description - Plants dull green. Stems monomorphic, unbranched and branched, to 10 mm long x 2 mm wide; rhizoids basal and axillary, smooth, reddish; axillary hyaline nodules present or absent; epidermis and outer 1-2 tiers of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled, hyaline; central strand present or absent. Leaves inrolled from tips when dry, distant to loosely imbricate, as many as 28 pairs, usually fewer, oblong, broadly acute to apiculate, each ending in a clear, sharp cell, to 1.7 mm long x 0.5 mm wide, perichaetial leaves often largest; margin serrulate on dorsal and ventral laminae, limbate on vaginant laminae of most leaves, extending 1/2-2/3 length of vaginant laminae, small or depauperate plants elimbate, limbidial cells unistratose; costa percurrent or ending 1-2 cells below apex, bryoides type; dorsal lamina mostly rounded at insertion; vaginant laminae of cauline leaves 2/3 leaf length, acute, ± equal, acute; laminal cells distinct, eguttulate, unistratose, firm-walled, unipapillose, some cells often bipapillose, mostly quadrate to hexagonal, 6-8 µm, juxtacostal cells in proximal parts of vaginant laminae somewhat larger, 11-26 µm. Monoicous (rhizautoicous, gonioautoicous, cladautoicous); perigonial stems usually shorter than perichaetial stems, sometimes gemmiform around base of perichaetial stems or axillary; perichaetia terminal on stems and branches. Sporophytes 1 per perichaetium, yellow, darkening with age; seta smooth, 2-5 mm long; theca exserted, erect, radially symmetric, 0.3-0.7 mm long, stomatose, exothecial cells quadrate, collenchymatous; peristome scariosus type; operculum conic, long rostrate, to 0.7 mm long. Spores smooth, 11-16 µm diam. Calyptra cucullate, smooth, 0.5 mm long.

Discussion:Fissidens homschuchii is similar to F. elegans; both species have leaves that terminate in a clear, sharp cell. The laminal cells of F. homschuchii, however, are mostly unipapillose while those in F. elegans are essentially pluripapillose. The limbidium in F. homschuchii is variable just as it is in F. elegans, and although it is expressed on all leaves of well-developed plants, it is lacking from most or all leaves of depauperate or poorly developed plants. The shorter limbidium will distinguish the species from F. submarginatus which has a limbidium that extends the entire length of the vaginant laminae and sometimes a short distance on the adjoining ventral lamina.

As discussed by Pursell (1989), Florschütz (1964) designated, in error, a neotype for F homschuchii that drastically altered the circumscription.
Distribution:Pernambuco Brazil South America| Risaralda Colombia South America| Saint-Laurent-du-Maroni French Guiana South America| Saint John Virgin Islands of the United States South America| Sint Eustatius South America| Guadeloupe South America| Baja Verapaz Guatemala Central America| Alajuela Costa Rica Central America| Cartago Costa Rica Central America| Heredia Costa Rica Central America| San José Costa Rica Central America| San Cristóbal Dominican Republic South America| Puerto Rico South America| Saint Thomas Virgin Islands of the United States South America| Nevis Saint Kitts and Nevis South America| Antioquia Colombia South America| Tolima Colombia South America| Para Suriname South America| Sipaliwini Suriname South America| Napo Ecuador South America| Loreto Peru South America| Alagoas Brazil South America| Amazonas Brazil South America| Distrito Federal Brazil South America| Espirito Santo Brazil South America| Goiás Brazil South America| Maranhão Brazil South America| Mato Grosso do Sul Brazil South America| Minas Gerais Brazil South America| Pará Brazil South America| Paraná Brazil South America| Pernambuco Brazil South America| Piauí Brazil South America| Rio de Janeiro Brazil South America| Rio Grande do Sul Brazil South America| Santa Catarina Brazil South America| São Paulo Brazil South America| Beni Bolivia South America| Alto Paraguay Paraguay South America| Chile South America| Jujuy Argentina South America| Virgin Gorda Virgin Islands South America| Water Island Virgin Islands South America| Antigua and Barbuda South America| Montserrat South America| Saint Kitts Saint Kitts and Nevis South America|