Fissidens ah-pengae 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 : 11-13

Fissidens ah-pengae Brugg. -Nann.

( Fig. 2 )

Fissidens ah-pengae is characterized by wide, elimbate, oblong to oblong-lingulate leaves with rounded-obtuse tips, limbidia weak, restricted to the vaginant laminae of perichaetial leaves, smooth laminal cells, costae that end 2-6 cells below the leaf tips and undivided, densely papillose peristome teeth. It is the only corticolous subgen. Polypodiopsis species in Africa with smooth laminal cells. Corticolous on tree-ferns in lowland rainforest.

Peristome

Erect with slightly incurved distal parts (both dry and wet), ±undivided, (seemingly?) perforated ( Fig. 2A, B ), densely and coarsely papillose, ±100 µm long, 26-30 mm wide at base; distal parts breaking off easily.

Ornamentation

OPL trabeculae thin, most distinct in basal cells ( Fig. 2A ); mid and distal part coarsely papillose interspersed with “perforations”; IPL trabeculae of basal IPL cells with a papillose border ( Fig.2C ), IPL in mid and upper part with irregularly thickened, papillose plaques forming a pattern of 3(-4) irregular columns that disturb the normal IPL structure of two columns ( Fig. 2B, D ).

Sporophyte

Seta ± 1 mm long, smooth; capsule cylindrical, 0.4 × 0.3 mm, exothecial cell columns ± 32, the cells quadratic-oblong to oblong; operculum not observed; spores ±15 µm in diam., smooth.

Description and illustration

Bruggeman-Nannenga (2009: fig.1); Bruggeman-Nannenga & Arts (2010: fig. 18).

Remarks

In this species the OPL is difficult to distinguish from the through-shining IPL. It is not clear whether the perforations are thin areas or true perforations. The peristome of F. ah-pengae resembles that of F. punctulatus Sande Lac. in being densely and coarsely papillose and seemingly perforated.

Figures

FIG. 2. —Fissidens ah-pengae Brugg.-Nann. A, OPL with focus on the thin trabeculae;B, OPL focus on the through-shining 3-4 irregular columns IPL cells;C, two IPL trabeculae with a papillose margin; D, IPL; E, moist capsule with ±erect, gently incurved teeth. All from holotype, La Réunion, Commune de Saint-Philippe, Ah-Peng & Bardat s.n., private herbarium Bruggeman-Nannenga. Scale bars: A-D, 20 µm; E, 0.4 mm.