Fissidens rotundifolius Brugg.

Bruggeman-Nannenga, Maria Alida, 2022, On the peristomes of the corticolous African species of Fissidens Hedw. (Fissidentaceae, Bryophyta), Cryptogamie, Bryologie 20 (2), pp. 9-36 : 28

Fissidens rotundifolius Brugg. -Nann.

( Fig. 17 )

Fissidens rotundifolius is characterized by wide oblong-lingulate leaves with rounded obtuse apices and distally spurred costae that end 3-9 cells below the apex, firm-walled laminal cells that appear smooth, but are mammillose. It has undivided, small peristomes.Without a peristome it could be mistaken for F. serratus Müll.Hal. The two can be separated by the more distinctly serrulate margins (coarsely serrulate margins on the basal part of the vaginant laminae) and distinctly mammillose laminal cells of F. serratus . Furthermore, F. serratus has a scariosus - type peristome. – On bark sparsely mixed with F. diaphanodontus .

Peristome

Extremely small, incurved when wet, undivided; teeth ±60-100 µm long, tooth base 23 µm wide.

Ornamentation

OPL four basal cells with smooth trabeculae that taper from the broad base to a thin edge, lamellae hard to observe, probably smooth, distal parts densely papillose; IPL trabeculae of basal part conspicuous, smooth; distal part with oblique ridges.

Sporophyte

Seta 1 mm long, smooth, basal part somewhat rugose; capsule cylindrical, 0.3 × 0.1.5- 0.2 mm with exothecial cell columns 22-32, the cells oblong, thin-walled; operculum not seen; spores subglobose, 19-21.5 × 17-19 µm, papillose.

Description and illustration

Bruggeman-Nannenga (in press: 43; fig. 5).

Figures

FIG. 17. — Fissidens rotundifolius Brugg.-Nann. A, OPL; B, capsule mouth with peristome teeth. Both from holotype: Tanzania, Hunga Valley below Amani, East Usambara Mts. Pócs & Jones s.n., EGR, between F. diaphanodontus. Scale bar: 50 µm.