Fissidens lateralioides Okam., J. Coll. Sci. Imp. Univ. Tokyo 38(4): 6. 1916.

Plants small, light green to green. Leafy stems 3.1–12.0 mm long, 2.0–4.0 mm wide, simple or often with lateral short branches at median to upper parts; cortical stem cells small, thick-walled; central strand weakly differentiated; axillary hyaline nodules not differentiated. Leaves in 5–15 pairs, upper stem leaves lanceolate to linear-lanceolate, 1.4–2.4 mm × 0.3–0.7 mm, acute at apex, wedge-shaped (rarely round) at base of dorsal laminae, rarely shortly decurrent; costa usually shortly excurrent; leaf margins almost entire, but weakly serrulate near apex; vaginant laminae 1/2 – 3/5 the leaf length, usually nearly equal at upper ends; limbidia usually strong, 2–4 rows of cells on apical laminae, 3–6 rows on vaginant laminae, 1–3 cells thick; laminae 1 cell thick; cells of apical laminae irregularly hexagonal to quadrate, 7–14 µm long, moderately thick-walled, smooth, rarely more or less weakly mammillose; cells of vaginant laminae similar to those of apical laminae, but longer and larger toward the base. Autoicous or polyoicous; male inflorescences bud-like, usually in axils of stem leaves, rarely terminal on stems; female inflorescences lateral (in axils of stem leaves), or terminal on stems, often terminal on short branches; archegonia often mixed with antheridia (synoicous), especially in terminal inflorescences; only one inflorescence found in each leaf axil; perchaetial leaves small for lateral female inflorescences, but larger for terminal synoicous inflorescences; archegonia 250–300 µm long. Setae relatively short, 0.8–2.5 mm long, smooth; capsules symmetrical, urn 0.5–0.9 mm long; opercula rostrate, 0.4–0.5 mm long; exothecial cells rectangular with thicker longitudinal walls; peristome teeth similar to those of var. bryoides, 0.4 mm long, 35–45 µm wide at base. Calyptrae cucullate. Spores 10–16(–21) µm in diameter, almost smooth.

Type. Japan: Kiushu, Nagasaki, Wichura 1413a (lectotype H-BR).

Chinese specimens examined: TAIWAN: Nan-tou Co., S.-H. Lin 452a, 453a (NICH, TUNG).

Habitat: on stones; Distribution: China, Japan, and Korea.

This variety is characterized by having lateral setae or having female inflorescences and perichaetial leaves much smaller than stem leaves. The variety was reported from Guizhou (Tan et al. 1994) and Shanghai (D.-K. Li and C.-H. Gao 1986), but we could not confirm these reports.

Illustrations: Pl. 69, figs. 8–31.