Trocholejeunea sinensis J.Wang

Wang, Jian, Gradstein, S. Robbert, Cheng, Xia-Fang & Zhu, Rui-Liang, 2014, A new species of Trocholejeunea (Lejeuneaceae, Marchantiophyta) from China, Phytotaxa 174 (5), pp. 296-300 : 296-297

Trocholejeunea sinensis J.Wang bis, R.L.Zhu & Gradst., sp. nov. ( Figs. 1–2 )

A new species characterized by the branches usually of Frullania - type and occasionally of Lejeunea - type; the hexagonal median cells with cordate trigones and homogeneous oil bodies; the lobule always with 3 teeth and the first tooth situated at the extreme end of the free margin near the junction of the lobule and the lobe; the gynoecia with 1–2 Frullania - type innovations; and the perianths with 9–10 straight or somewhat flexuose keels.

Type: — CHINA. Guangxi. Jinxiu Co., Dayaoshan National Nature Reserve, Cathaya argyrophylla Protection Station , on rotten logs, 900–1000 m, 19 Jul. 2009, Wen Ye & Yu-Mei Wei 20090719-47 A (holotype HSNU!) .

Dioicous? (Androecia not seen). Plants 1.6–2 cm long, 1.1–1.8 mm wide, yellowish green, brown when dry, irregularly branched, branches predominantly of the Frullania - type (long branches), occasionally of the Lejeunea - type (short branches). Stems 0.12–0.16 mm in diameter, ventral merophyte 4–6 cells wide, stem in transverse section with 14–15 cortical cells and 20–21 medullary cells. Rhizoids few, fasciculate, brown, rhizoid disc absent. Leaves imbricate, clasping the stem when dry, widely spreading and convex when moist, not becoming squarrose, the apex recurved. Lobe ovate-oblong, 0.8–1.1 mm long, 0.5–0.7 mm wide, the apex obtuse or rounded-obtuse, recurved, margin entire. Lobe cells thin-walled, sometimes slightly thickened, trigones cordate, intermediate thickenings occasionally present, marginal cells quadrate to rectangular, 12–22×12–20 µm, median cells usually elongate-hexagonal, 30–44×14–24 µm, basal cells elongate-hexagonal, 34–48×16–28 µm. Cuticle smooth. Oil bodies 16–30 per median cell of leaf lobe, homogeneous, narrowly oblong to oblong, 3.0–6.2×1.3–2.5 µm, smooth on surface. Ocelli and vitta absent. Lobule oblong or ovate-rectangular, 1/2–3/5 as long as the lobe, free lateral margin not incurved, apex obliquely truncate, with 3 teeth, the teeth 1–2 cells long, the first tooth situated at the extreme end of the free margin, hyaline papilla two cells below the base of the second tooth. Underleaves imbricated, orbicular-quadrate to transversally ovate, 0.4–0.6 mm long, 0.5–0.7 mm wide, 3–5 times as wide as the stem, the apex rounded, recurved, the bases with a sinuate insertion line. Androecia not seen. Gynoecia terminating on stem or branch, with 1–2 Frullania - type innovations, bract lobes 2, oblong-ovate, 1.0– 1.2 mm long, 0.56–0.64 mm wide, obtuse or rounded-obtuse at apex, margin entire, bract lobule absent or present, if present rectangular, ca. 1/2 as long as the bract lobe, apex obtuse; bracteole usually 1, rarely 2, similar to underleaves in shape, 0.7–0.8 mm long, 0.6–0.7 mm wide, the apex rounded and recurved, margin entire. Perianth obovate, 1.1–1.4 mm long, 0.7–0.9 mm wide, with 9–10 keels, keels somewhat flexuose, beak 1 cell long. Asexual reproductive organs not seen.

Ecology and distribution: — Trocholejeunea sinensis occurs in relatively open forests and was collected at ca. 900 to 1900 m. The new species grows on tree bark and rotten logs in association with Lejeunea curviloba Steph. and Frullania tamarisci (L.) Dumort. It is thus far known only from Guangxi and Yunnan, China.

Additional specimen examined: — CHINA. Yunnan. Honghe State, Lvchun Co., Huanglianshan National Nature Reserve , on tree bark, 22°55’05.60’’ N, 102°17’07.80’’ E, 1906 m, 22 Nov. 2012, Jian Wang et al. 20121122-28 ( HSNU) .

Figures

FIGURE 1. Trocholejeunea sinensis. A. Shoot, ventral view, B. Shoot, dorsal view, C. Marginal lobe cells, D. Median lobe cells, showing cordate trigones, E. Basal lobe cells, F. Underleaves, G–I. Female bracteole, J. Female bract, K. Portion of shoot with perianth, ventral view, L. Cross section of perianth, M. Stem section, N. Leaves, O. Leaf lobule, showing 3 lobule teeth. All from Wen Ye & Yu-Mei Wei 20090719-47A.

FIGURE 2. Trocholejeunea sinensis. A. Shoot, ventral view, B. Shoot, dorsal view, C. Median lobe cells, showing homogeneous oil bodies, D. Marginal lobe cells, E. Stem section, F. Plants on tree bark, G, H. Underleaves, I, J. Leaves, K. Leaf lobule, showing 3 lobule teeth.All from Jian Wang et al. 20121122-28.