Fissidens pseudoanomalus Brugg., 2020

Bruggeman-Nannenga, Maria A. & Müller, Frank, 2020, A contribution to the Fissidens Hedw. (Musci, Fissidentaceae) of Myanmar, including F. strictidens sp. nov. and F. pseudoanomalus sp. nov., Cryptogamie, Bryologie 20 (18), pp. 229-238 : 233

Fissidens pseudoanomalus Brugg. -Nann. & Frank Müll., sp. nov.

( Figs 3-5 )

DIAGNOSIS. — The species closely resembles Fissidens anomalus Mont. , but differs in the structure of the leaf border zone which is in part bistratose and contains elongated cells.

HOLOTYPE. — Myanmar, Hponyin Razi , Lithocarpus - Magnolia - Rhododendron forest, 2632 m, 27.616607N, 96.982848E, 30.X.2013, G. Miehe et al. 13-076-075- F (holo-, DR; iso-, L).

FURTHER SPECIMENS EXAMINED (paratypes). — Myanmar, Kachin State, Hponkan Razi, evergreen broadleaved forest, 1360 m, 27.58421N, 97.10447E, 24.X.2014, J. Kluge & P. K. Kine 14-050- 12e-A ( DR, private herbarium Bruggeman-Nannenga); Myanmar, Kachin State, Hponkan Razi, Quercus -Magnolia - Araliaceae forest, 1833 m, 27.603756N, 96.988924E, 16.XI.2013, G. Miehe et al. 13-093-202- B ( DR, private herbarium Bruggeman-Nannenga).

DESCRIPTION

Stems

Up to 35 mm long and up to 8 mm wide, pinnately foliated, sparsely to heavily branched, central strand well developed.

Rhizoids

Dark red-brown, heavily branched, smooth.

Axillary nodules

Not differentiated.

Leaves

Close to distant, up to 30 pairs, crispate when dry, lanceolate, often falcate, with acute-acuminate apex, 2.4-5.6 × 0.4- 0.95 mm, 5-6 times as long as wide, margin coarsely serrate on dorsal and apical lamina, on the vaginant laminae serrulate with a few distant larger teeth; apical and dorsal lamina with pale, thickened, 3-5 cells wide, uni- to bistratose border of isodiametric and partly elongated cells, margin of vaginant lamina unistratose, hardly differentiated; vaginant laminae

½-ª/5 the leaf length, rounded at insertion, unistratose, slightly unequal; dorsal lamina rounded-truncate below, reaching the insertion, not decurrent; dorsal and apical lamina unistratose.

Costa

Long excurrent, in cross-section taxifolius-type.

Lumina

Of mid dorsal laminal cells (6.5-)9.5-10.5(-13.0) × (5-)6.5- 7.5(-9) µm, walls smooth, convex, thin, 1-1.5 µm wide; lumina of mid vaginant laminal cells (8.5-)10-10.7(-12.1) × (5-)6- 6.9(-8.2) µm; walls 2-3 µm wide, smooth; marginal cells of vaginant lamina with more incrassate, 3-4(-5) µm wide walls.

Gemmae

Not observed.

Fertile parts

Perigonia not observed. Perichaetia terminal on axillary, short, 1.6-2.5 mm long branches, archegonia 350-450 µm long, perichaetial leaves 1.5-2.1 mm long; calyptra not observed. Sporophyte, seta 3 mm long, smooth, 1 per perichaetium; capsule erect, 1.5 × 1.0 mm, with ± 94 columns of oblong exothecial cells with thick vertical walls, with stomata; peristome taxifolius-type, teeth deeply divided, ± 500 µm long, tooth-base 42-51 µm wide; operculum not observed; spores subglobose, 18.5-22(-25) × 16-20 µm, papillose.

DISCUSSION

The new species is easily recognized by its large size, the elimbate leaves with a pale, partly bistratose border-zone with elongated cells, coarsely serrate margins and lateral sporophytes with short setae and the reduced taxifolius-type peristome. It is closely resembles F. anomalus Mont. that has a similar sporophyte and a similar peristome. The two differ in the structure of the border zone. That of the new species is in part bistratose and contains elongated cells next to isodiametric cells. In F. anomalus the border zone is unistratose and composed of isodiametric cells. One of the paratypes, Miehe et al. 13-093- 202-B, differs from the other two in having bistratose areas in the dorsal lamina ( Fig. 4C lowest cross section). In this respect it resembles F. dubius P.Beauv. and it will key out as that species (e.g., Li & Iwatsuki 2001). It can be distinguished from F. dubius by the structure of the border zone. That of F. dubius is unistratose and is composed entirely of isodiametric cells.

Figures

FIG. 3. — Fissidens pseudoanomalus sp. nov.: A, leaf near insertion (left) and mid leaf (right); B, leaf apex; C, trans section of leaf above the vaginant lamina; D, margins of mid leaf. A, B, C, D (right and left) from holotype G. Miehe et al. 13-076-075-F, D (middle) from G. Miehe et al.13-093-202-B. Scale bars: A, 200 µm; B, 100 µm; C, D, 50 µm.

FIG. 4. — Fissidens pseudoanomalus sp. nov.: A, perichaetial branches; B, stem with perichaetial branches; C, part of trans section of leaf above vaginant laminae showing the bistratose border zone; D, leaves. A, C (two top cross sections), D from holotype G. Miehe et al. 13-076-075-F; B, C (lowest cross section) from G. Miehe et al. 13-093-202-B. Scale bars: A, 100 µm; B, D, 1 mm; C, 50 µm.

FIG. 5. — Fissidens pseudoanomalus sp. nov.: A, sporophyte; B, upper part of peristome teeth; C, median part of peristome teeth; D, exterior side of basal part of peristome teeth. A-D from holotype Miehe et al. 13-076-075-F. Scale bars: A, 1 mm; B-D, 50 µm.