Monographs Details: Fissidens serratus var. serratus
Authority: Pursell, Ronald A. 2007. Fissidentaceae. Fl. Neotrop. Monogr. 101 (Published by NYBG Press)
Family:Fissidentaceae
Synonyms:Fissidens serratus Müll.Hal., Conomitrium serratum (Müll.Hal.) Müll.Hal., Fissidens donnellii Austin, Conomitrium puiggarii Geh. & Hampe, Fissidens puiggarii (Geh. & Hampe) Paris, Fissidens prionodes f. puiggarii (Geh. & Hampe) Florsch., Conomitrium trachelymum Sull., Fissidens trachelyma (Sull.) Broth., Fissidens tenerrimus Müll.Hal., Conomitrium tenerrimum Müll.Hal., Fissidens dimorphus Müll.Hal., Conomitrium trichopodium Müll.Hal., Fissidens iporanganus Besch. & Geh., Fissidens crenatoserrulatus Cardot, Fissidens tocoraniensis Herzog, Fissidens vardei Thér., Fissidens jamaicensis E.Britton, Fissidens echinellus Herzog, Fissidens buckii Pursell
Description:Variety Description - Plants light green. Stems monomorphic, usually unbranched, 1.5-5.0 mm long x 1.5-2.0 mm wide; rhizoids basal, smooth, reddish; 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 when dry, usually loosely imbricate, as many as 9 pairs, most often palmately arranged on short stems, occasionally pinnately arranged on longer stems, lanceolate to narrowly lanceolate, 2.7 mm long x 0.1-0.4 mm wide, usually sharply acute, sometimes obtuse-apiculate; margin elimbate, crenulate-serrulate on dorsal and ventral laminae, ± coarsely serrate on vaginant laminae, or limbate, ± entire on proximal 1/2 or less of perichaetial leaves, limbidium marginal, limbidial cells unistratose; costa ending 2-8 cells below leaf apex or percurrent to short-excurrent, bryoides type; dorsal lamina somewhat narrowed proximally, ending at the insertion or above; vaginant laminae of cauline leaves ± 1/2-2/3 leaf length, acute, unequal, minor lamina ending near leaf margin; laminal cells distinct, eguttulate, unistratose, firm-walled, mammillose, irregularly quadrate to hexagonal, 6-13 µm, marginal cells frequently broader than long, juxtacostal cells of vaginant laminae larger, ± quadrate to oblong, often pellucid, 12-30 µm long, smooth. Monoicous (gonioautoicous, possibly also rhizautoicous); perigonia gemmiform, axillary or terminal on short stems, basal to perichaetial stems; perichaetia terminal on stems. Sporophytes 1-2 per perichaetium, yellow, darkening with age; seta smooth, 2-7 mm long; theca exserted, erect, radially symmetric, 0.30.6 mm long, stomatose, exothecial cells quadrate to oblong, vertical walls thicker than horizontal walls, collenchymatous; peristome scariosus type; operculum, conic, long-rostrate, 0.4-0.5 mm long, as long as or nearly as long as theca. Spores smooth, 7-14 µm diam. Calyptra cucullate, smooth to prorate, 0.4-0.6 mm long.

Discussion:Synonyms from outside the area of this study (Brugge-man-Nannenga & Pursell, 1995; Dirkse et al., 1991; Iwatsuki & Suzuki, 1989): Conomitrium wilsonii Miill. Hal., Fissidens australiensis A. Jaeger, Fissidens eenii Bizot, Fissidens papillosus Sande Lac. (non Fissidens papillosus Thwaites & Mitt, in Mitt.), Fissidens perangustifolius Broth. & Paris in Broth., Fissidens pseudo-serratus (Miill. Hal.) A. Jaeger, Fissidens sparsus Broth. & Paris in Broth., Fissidens subexasperatus Bizot & Dury ex Pócs, and Fissidens tenellus Hook. f. & Wilson.

Fissidens serratus var. serratus is best recognized by its coarsely serrate leaf margin, especially on the vaginant laminae, and mammillose laminal cells. Its leaves can at times be pinnately arranged, and the leaf margin, particularly on the vaginant laminae of perichaetial leaves, can be limbate and more or less entire. Such an expression can be confused with F. lagenarius, particularly if it occurs on tree bark. When sporophytes are present, however, the typical scariosus type of peristome of F. serratus will distinguish it from F. lagenarius which has densely papillose and more or less undivided peristome teeth. In the absence of sporophytes, the larger plants and perigonia in the axils of leaves subtending the perichaetia of F. lagenarius will distinguish this species from F. serratus var. serratus. Fissidens steerei might also be confused with F. serratus var. serratus. However, the oblong-ovate leaves and short costa of F. steerei will distinguish this species from F. serratus.

Distribution and Ecology: Mexico (Campeche, Chiapas, San Luís Potosí, Tamaulipas, Veracruz); Central America (Belize, Costa Rica, Guatemala, Honduras); West Indies (Bermuda, Cuba, Dominican Republic, Jamaica, Puerto Rico); South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Suriname, Venezuela); on soil, tree trunks, and rotting wood; 10-3000 m. This variety has been reported recently as new to Venezuela (Ussher & León Vargas, 2003). Although I have not seen the specimen that this report is based on, I have examined other specimens from Venezuela. The variety also occurs in the southeastern United States (Florida), tropical Africa, Tristan da Cunha, Macaronesia, Australasia, and Asia.

Distribution:Campeche Mexico North America| Chiapas Mexico North America| San Luis Potosí Mexico North America| Tamaulipas Mexico North America| Alta Verapaz Guatemala Central America| Quezaltenango Guatemala Central America| Belize Belize Central America| Cayo Belize Central America| Toledo Belize Central America| Lempira Honduras Central America| Puntarenas Costa Rica Central America| San José Costa Rica Central America| Bermuda South America| Jamaica South America| Independencia Dominican Republic South America| Puerto Rico South America| Antioquia Colombia South America| Magdalena Colombia South America| Aragua Venezuela South America| Miranda Venezuela South America| Mazaruni-Potaro Guyana South America| Sipaliwini Suriname South America| Carchi Ecuador South America| Oriente Ecuador South America| Minas Gerais Brazil South America| Pernambuco Brazil South America| Rio Grande do Sul Brazil South America| Santa Catarina Brazil South America| São Paulo Brazil South America| Paraguarí Paraguay South America| Valparaíso Chile South America| Buenos Aires Argentina South America| Tucuman Argentina South America|