Fissidens pseudoscindulatus Brugg., 2022

Bruggeman-Nannenga, Maria Alida, 2022, Five new species of Fissidens Hedw. (Fissidentaceae, Bryophyta), taxonomic notes and a new species record for South Africa, Cryptogamie, Bryologie 20 (3), pp. 37-49 : 43

Fissidens pseudoscindulatus Brugg. -Nann., sp. nov.

( Fig. 4 )

Cryptogamie, Bryologie 43 (2): 27 nomen nudum.

HOLOTYPE. — Brazil. Goiás State, c. 18 km S of Itaberai Town , on tree trunk, in plateau forest, 28.XII.1974, D. Vital 4992 with F. lagenarius Mitt. (holo-, L; iso-, SP).

ADDITIONAL SPECIMEN (PARATYPE). — Brazil. São Paulo State, Município de Mogi Guaçu, at fazenda Sete Lagoas, on bark of small tree trunk, in a small area of secondary forest, 2.II.1977, D. Vital 6946 mixed with F. lagenarius Mitt. (private herbarium Bruggeman-Nannenga; SP).

ETYMOLOGY. — This species has been named for its cells with somewhat overlapping papillae. These resemble scindulose cells, but are pluripapillose. Hence “pseudoscindulatus ”. From scindula or scandula: wooden; pseudo: false.

ECOLOGY. — On bark of small tree trunk, in a small area of secondary forest and in a plateau forest.

DESCRIPTION

Stem 1-4 × 1-1.4 mm, branched or not, pinnately foliated, with central strand; rhizoids brown and smooth; axillary nodules not differentiated; leaves close to distant, up to 14 pairs, crispate when dry, lanceolate, with acute apex, 0.6-1.0 × 0.2 mm, (3.0-)4.0-4.5 times as long as wide, margin crenulate, elimbate except for the vaginant laminae of perichaetial leaves; limbidia reaching up to about half the length of the vaginant lamina, reaching the insertion or not, unistratose, marginal; vaginant lamina ½-³⁄5 of the total leaf length, at the base narrower than the stem, unequal, unistratose; dorsal lamina slightly rounded to rounded at the insertion, reaching the insertion, not decurrent; dorsal and apical lamina unistratose; costa ending 1-3 cells below the apex, in cross-section bryoides - type;

lumina of mid dorsal laminal cells 3.5-6.5 × 2.5-4.5 µm, 1-3 papillose (most easily observed in 5 % KOH); lumina of mid vaginant laminal cells 3.5-8.0 × 2.0-5.0 µm, 2-3 papillose. No gemmae observed.

Perichaetia and perigonia on separate stems, perigonia terminal; antheridia ± 140 µm long; perichaetia terminal on main stems and branches; archegonia 150-250 µm long; perichaetial leaves 0.9 mm long; calyptra not observed. Sporophyte: seta 1.7-1.9 mm long, smooth, 1 per perichaetium, capsule cylindrical, 0.5-0.7 × 0.25 mm with ±32 columns of oblong exothecial cells with thick vertical walls around the capsule; peristome straightening when moistened, undivided, basal ±3 cells more or less incurved, distal parts straight, teeth ± 160 µm long, tooth base 24-29 µm wide; OPL of basal 3-5 cells with high, smooth trabeculae ( Fig. 4H ), trabeculae becoming less distinct in distal direction, OPL lamellae in mid tooth with well-developed ornamentation ( Fig. 4J ); lamellar IPL ornamentation in mid tooth consisting of high, oblique, close ridges ( Fig. 4G, I ), filaments distally papillose on both sides; operculum rostrate, 0.25 mm long; spores subglobose to ellipsoid, 11.0-17.5 × (7.0-) 9.5-15.5 µm, faintly to coarsely papillose.

This corticolous species is characterized by limbidia restricted to the perichaetial leaves, undivided peristomes with a characteristic OPL-ornamentation on the mid part and pluripapillose laminal cells with papillae overlap neighboring cells somewhat ( Fig. 4F ). It is most likely to be confused with other neotropical species adorned with anomalous peristomes. These peristomes are usually species-specific. They are described and figured by Pursell (2007). Most species with anomalous peristomes are corticolous, but F. michoacanus Thér. grows on rock and soil, whereas F.termitarum (Herzog) Pursell typically lives on termite mounds, though it is also known from bark. Apart from in their peristomes, the neotropical species with anomalous peristomes differ from the new species as follows. Fissidens lagenarius Mitt. has rather similar peristomes, but has mammillose laminal cells. Fissidens termitarum is distinct by mammillose laminal cells, F. cylindrothecus Pursell & J. Aguirre differs by its smooth laminal cells, deeply divided peristome teeth and collenchymatous exothecial cells (exothecial cells of the new species have thickened vertical walls, but no incrassate corners). The pluripapillose F. michoacanus and F. gardneri Mitt. also have anomalous peristomes. The first can be distinguished from F.pseudoscindulatus by its short costae ending 12-20 cells below the apex and F. gardneri by its strongly unequal vaginant lamina where the minor lamina ends at or near the costa, and its wide, obtuse leaf tips.

Figures

FIG. 4. — Fissidens pseudoscindulatus, sp. nov. A, sporophytic stem; B, leaf; C, leaf apex; D, mid leaf; E, leaf insertion; F, pseudo-scindulose mid vaginant laminal cells; G, peristome, OLP (two teeth on the left) and IPL (on the right); H, basal OPL of two teeth; I, detail of IPL; J, detail of OPL showing the characteristic ornamentation of the mid part (all from holotype). Scale bars: A, 1 mm; B, 0.5 mm; C-E, G, 50 µm; F, H-J, 20 µm.