Fissidens pseudoanomalus Bruggeman-Nannenga & Müller 2020, sp. nov.
Creators: name: Bruggeman-Nannenga, Maria A.
name: Müller, Frank
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Bryopsida
Fissidentales
Fissidentaceae
Fissidens
Fissidens pseudoanomalus

description: 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.
description: Published as part of 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., pp. 229-238 in Cryptogamie, Bryologie 20 (18) on page 233, DOI: 10.5252/cryptogamie-bryologie2020v41a18, http://zenodo.org/record/7822194