4. Regmatodon serrulatus (Dozy & Molk.) Bosch & Sande Lac. 齿边异齿藓 chi-bian yi-chi xian
Bryol. Jav. 2: 111. 1864. Macrohymenium serrulatum Dozy & Molk., Musci Frond. Ined. Archip. Ind. 6: 170. 56. 1848. Type. Indonesia: Java.
Plants rigid, yellowish green to greenish brown, slightly shiny, ca. 2–3 cm long. Primary stems creeping, lateral stems ascending, 1–2 times irregularly pinnately branched, branch apices taper-pointed. Leaves ovate to broadly ovate, acuminate or acute upward, 0.7–1.5 mm × 0.3–0.7 mm; leaf margins obviously unicellularly dentate above middle part, slightly involute on one side at base; costa single, thick, strong, ending at 1/2–2/3 the leaf length; leaf cells thick-walled; median and upper cells irregularly rhomboidal, 7–12 µm × 4–5 µm, several rows of cells at basal margins, subquadrate; basal cells near costa slightly elongate. Monoicous. Setae erect, coarsely papillose; capsules cylindrical; exostome teeth short; endostome segments well developed; opercula obtusely rostellate.