Monographs Details: Fissidens radicans Mont.
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Family:Fissidentaceae
Scientific Name:Fissidens radicans Mont.
Synonyms:Conomitrium radicans (Mont.) Müll.Hal., Fissidens flavicans Schimp., Fissidens santa-clarensis var. obtusifolius Bizot & Thér., Fissidens perramosus Broth.
Description:Species Description - Plants light green. Stems monomorphic, to 7.5 mm long x 1.75-2.50 mm wide, unbranched or branched; rhizoids basal, smooth, reddish; axillary hyaline nodules absent; epidermis and outer 1-2 tiers of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled; central strand present or absent. Leaves inrolled from tips, ± crispate when dry, conspicuously caducous in most collections, imbricate, as many as 21 pairs, oblong-lingulate, broadly acute to rounded, often undulate, 1.0-1.8 mm long x 0.20-0.35 mm wide; margin crenulate, elimbate; costa ending 5-18 cells below leaf apex, oblongifolius type, distal part in transverse section showing 2 stereid bands separated by 4 enlarged cells arranged in 2 rows; dorsal lamina narrowed, ending at or near insertion; vaginant laminae of cauline leaves 1/2-2/3 leaf length, acute, slightly unequal, minor lamina ending near margin or ± 1/2 the distance between costa and margin; laminal cells distinct, eguttulate, unistratose, firm-walled, lenticularly thickened in dorsal and ventral laminae, irregularly quadrate to hexagonal, 6-10 µm long, plane or somewhat bulging in vaginant laminae. Monoicous (cladautoicous); perigonia and perichaetia terminal on branches. Sporophytes 1 per perichaetium, yellow, darkening with age; seta smooth, 2-4 mm long; theca exserted, erect, radially symmetric, 0.40.9 mm long, stomatose, exothecial cells quadrate to oblong, vertical walls thicker than horizontal walls, collenchymatous; peristome anomalous, reduced, teeth undivided or irregularly divided, filaments irregularly ornamented; operculum not seen. Spores coarsely papillose, 17-20 µm diam. Calyptra not seen.

Discussion:The caducous leaves, evident with a hand lens, are often enough to separate this small Fissidens from F. dendrophilus and F. santa-clarensis. The undivided or imperfectly divided peristome teeth also help to distinguish it from those species. Broadly acute to obtuse leaves are characteristic of both F. radicans and F. dendrophilus, while leaves abruptly narrowed and obtuse-rounded are characteristic of F. santa-clarensis. The caducous leaves of F. radicans might function in vegetative reproduction, although this has not been demonstrated.
Distribution:Saint-Laurent-du-Maroni French Guiana South America| Sint Eustatius South America| Dominica South America| Chiapas Mexico North America| Quintana Roo Mexico North America| Belize Belize Central America| Toledo Belize Central America| Zelaya Nicaragua Central America| Guanacaste Costa Rica Central America| Colón Panama Central America| Panamá Panama Central America| Cuba South America| Puerto Rico South America| Bolívar Venezuela South America| Rupununi Guyana South America| Sipaliwini Suriname South America| Cayenne French Guiana South America| Loreto Peru South America| Pará Brazil South America| Paraíba Brazil South America| Pernambuco Brazil South America| São Paulo Brazil South America| Guadeloupe South America| Saint Thomas Jamaica South America| Virgin Gorda Virgin Islands South America|