Plagiothecium higuchii G.J.Wolski, 2023

Wolski, Grzegorz J., Khan, Aamir Shehzad & Paszko, Beata, 2023, New taxa of Plagiothecium (Plagiotheciaceae) from Pakistan, PhytoKeys 236, pp. 1-16 : 1

Plagiothecium higuchii G.J.Wolski sp. nov.

Type.

Pakistan, Mt. Nanga Parbat , Mazeno Base Camp, 4000 m alt, on soil, 15 September 1990, M. Higuchi 20460, holotype LOD15016 , isotype PMNH .

Description.

Plants green-yellow to golden-gold, without metallic luster; stems complanate-foliate, 3.0-4.0 cm long, in cross-section rounded, with a diameter of 290-360 (M 325) μm, the central strand well developed, epidermal cells 11-22 × 13-32 (M 16 × 22) μm, the parenchyma thin-walled, 26-50 × 23-45 (M 38 × 34) μm; leaves quite loosely arranged on the stem, concave, symmetrical to asymmetrical, ovate, those leaves from the middle of the stem 3.4-4.3 × 1.2-1.9 (M 3.8 × 1.5) mm; the apex acuminate and denticulate; costae two, thick and strong, usually to 1/2 of the leaf length, reaching 0.5-1.2 mm; laminal cells symmetrical, in unregulated transverse rows, the length and width very variable, but dependent on location: 107-250 × 16-24 (M 178 × 20) μm at apex, 139-266 × 21-33 (M 203 × 27) μm at mid-leaf and 139-266 × 21-33 (M 203 × 27) μm towards insertion, cell areolation very loose; decurrency long, 300-500 (M 400) μm, composed of 4-6 rows of rectangular and spherically inflated cells, 48-144 × 26-70 (M 96 × 48) μm. Sporophytes so far unknown (Fig. 3 ). In these studies, Plagiothecium higuchii var. higuchii (M. Higuchi 20460) has been recorded on soil.

Etymology.

The present species is named in honor of Professor Masanobu Higuchi, who participated in the Studies on Cryptogams in the Western Himalayas in Pakistan project, and who collected the specimen (Higuchi 20460) chosen here as the holotype of Plagiothecium higuchii .

Figures

Figure 3. The most important taxonomic features of Plagiothecium higuchii var. higuchii A apex serration B, C dimension of cells (B from the middle C basal part of the leaf) D decurrent cells E, F leaf shape (from M. Higuchi 20460).