Cololejeunea nanhutashanensis J.D.Yang & S.H.Lin, 2014

Yang, Jia-Dong & Lin, Shan-Hsiung, 2014, Cololejeunea nanhutashanensis (Lejeuneaceae), a new species from Taiwan, Phytotaxa 177 (1), pp. 56-60 : 56-58

Cololejeunea nanhutashanensis J.D.Yang & S.H.Lin , sp. nov. ( Fig. 1 )

Diagnosis: Cololejeunea nanhutashanensis differs from the otherwise similar Cololejeunea biddlecomiae (Aust. in Pearson 1890: 5) Evans (1902: 168) in its leaves with obtuse to rounded apex; large leaf lobule to 2/3–3/4 of lobe length; stylus 5–16 cells long, 1–3 seriate; leaf cells thin-walled with large trigones and hemispherical dorsal protrusions; androecia terminal on short lateral branches with male bracts in 3–5 pairs; female bracts large, bract lobule almost as long as bract lobe; perianth obovate to oblong, 5-keeled, with dorsal protrusions on its upper 1/3 surface.

TYPE:— TAIWAN. Taichung City, Heping District, between Jiliting and the trailhead to the Mt. Nanhutashan , on trunk and mixed with lichen in a pure forest of Pinus taiwanensis Hayata , 24º22’N, 121º21’E, ca. 2600 m in elevation, 17 Sep 1975 , S.- H. Lin 7402 ( holotype: TUNG!; isotype: TAIE!) .

Plants yellowish brown to brown in color when dried, loosely appressed to the substrate, up to 5 mm long. Shoots 0.40–0.65 mm wide with leaves, irregularly branched, in Lejeunea - type. Stems 33–82 μm in diameter. Rhizoids usually fasciculate, hyaline, and its initial-area in groups of 4–6 cells. Leaves imbricate; lobe obliquely spreading, plane or slightly convex, ovate to broadly ovate; 0.22–0.39 mm long, 0.21–0.28 mm wide; apex obtuse to rounded; margin crenulate-papillose. Cells of leaf lobe thin-walled; trigones large; intermediate thickenings usually small or indistinct; marginal cells subquadrate to rectangular, 10–12 × 7–10 μm; median cells hexagonal, 10–15 × 9–12 μm; basal cells elongate, 16–26 × 11–15 μm, dorsal protrusions of leaf cells hemispherical, 1 per cell, 6–11 μm in diameter. Oil bodies unknown. Ocelli and vitta absent. Leaf lobule large, ovate to elliptical, 0.19–0.30 mm long, 0.13–0.17 mm wide, 2/3–3/4 as long as the lobe, inflated, smooth on ventral surface; free lateral margin slightly incurved and bordered with more than 10 subquadrate to rectangular cells; apex with 2 teeth, separated by 2–4 cells from each other; first tooth 2–3 cells long, 1 cell wide; second tooth 1–2 cells long, 1 cell wide; hyaline papilla spherical, on the inner surface of first tooth; keel arched, papillose. Stylus large, linear, 5–16 cells long, in 1–3 seriate. Autoicous. Androecia terminal on long or short lateral branches; bracts in 3–5 pairs, imbricated, similar to the leaves; apex often incurved; bract lobule ovate, 2/3–3/4 as long as the bract lobe, inflated; antheridia borne singly. Gynoecia terminal on short lateral branches; bract lobe obovate, 0.40–0.70 mm long, 0.24–0.34 mm wide; apex obtuse; bract lobule oblong, almost as long as the bract lobe; apex rounded; keel almost as long as the bract lobule. Perianth obovate to oblong, almost immersed or emergent only up to its 1/ 5 in length, inflated, 0.56–0.64 mm long, 0.36–0.40 mm wide; apex rounded to truncate, 5 keeled, with dorsal protrusions on upper 1/3 surface. Gemmae not observed.

Etymology: —The specific epithet refers to Mt. Nanhutashan, where the new species was discovered.

Habitat and distribution: — Cololejeunea nanhutashanensis is an epiphyte found in altimontane forest. It grows on tree trunk of Pinus taiwanensis , in environment with filtered light and is currently known only from Mt. Nanhutashan, Taichung, Taiwan.

Figures

FIGURE 1. Cololejeunea nanhutashanensis. A. Cells of leaf apex. B. Median cells of leaf lobe. C. Basal cells of leaf lobe. D–L. Styli. M, N. Leaf lobules and styli. O. Leaf lobule. P. Ventral surface of stem, showing a stylus and two groups of rhizoids initial-area. Q, R. Leaves, ventral view. S. Leaf, dorsal view. T.Androecium, ventral view. U. Gynoecium, ventral view. V. Portion of the plant, ventral view. All from holotype.