Monographs Details: Fissidens incisus Herzog
Description:Species Description - Plants pale green. Stems dimorphic, delicate, unbranched or branched from older parts, infertile ones to 5 mm long x 1.5 mm wide, fertile ones to 1.5 mm long x 1.0 mm wide; rhizoids basal, smooth, reddish; axillary hyaline nodules present; epidermis and outer tier of cortical cells small, incrassate, pigmented; inner cortical cells larger, thin-walled, hyaline; central strand present or absent. Leaves ± crispate when dry, distant to imbricate, as many as 18 pairs on infertile stems, 3-4 pairs on fertile stems, lanceolate to ovate-lanceolate, acute to short-acuminate, 1.0-1.5 mm long x 0.2-2.5 mm wide, perichaetial leaves longest; margin entire, limbate on all laminae, limbidium usually reaching leaf apex, confluent with the costa, limbidial cells bi- to tristratose; costa percurrent to short-excurrent, bryoides type; dorsal lamina ending above or at insertion; vaginant laminae ± 3/4 leaf length, acute, ± equal on infertile stems, unequal on most leaves of fertile stems, minor lamina narrowed to costa; laminal cells distinct, eguttulate, unistratose, firm-walled, smooth, plane or slightly bulging irregularly quadrate to hexagonal, somewhat longer than wide, 9-16 µm x 5-11 µm wide, slightly larger in proximal parts of leaves. Monoicous (rhiza-utoicous); perigonial stems gemmiform at base of fertile and infertile stems; perichaetia terminal. Sporophytes 1 per perichaetium, yellow, darkening with age; seta smooth, to 4 mm long; theca exserted, erect, radially symmetric, 0.6-0.9 mm long, stomatose, exothecial cells quadrate to oblong, collenchy-matous; peristome anomalous, teeth fragile, erect when moist, somewhat unequally divided, proximal lamellae smooth, filaments strongly spiculose. Spores smooth, 9-13 µm diam. Operculum and calyptra not seen.
Discussion:Fissidens incisus is similar to F. curvatus; both species have dimorphic stems, an excurrent costa, a limbidium that is confluent or nearly so at the leaf apex, and similar laminal cells. However, the spiculose peristome teeth of F. incisus will distinguish it from any other species of Fissidens with dimorphic stems.
Distribution:Bolivia South America