Fissidens curvatus Hornschuch 1841

Fissidens curvatus is distinguished by its delicate dimorphic stems, usually long excurrent costa, limbidium confluent at leaf apex, and slightly elongate laminal cells. The theca is usually arcuate but can also be erect.

Fissidens strictulus was reduced to synonymy of F. curvatus by Bruggeman-Nannenga and Pursell (1995[1996]) based on an examination of the type specimen of F. subxiphioides.

Plants 1.2-10 × 1-2.5 mm. Stem unbranched and branched; axillary hyaline nodules present; central strand weak or absent. Leaves as many as 25 pairs, narrowly lanceolate to ovate-lanceolate, acute to sharply acute to short acuminate, to 1.9 × 0.3; dorsal lamina narrowed proximally, ending before or at insertion, infrequently ± decurrent; vaginant laminae ¹/2-⁴/5 leaf length, ± equal, minor lamina ending on or near margin; margin entire, limbate on all laminae, limbidium confluent at apex or ending shortly before apex, extending to base of dorsal lamina, limbidial cells 2-3-stratose; costa percurrent to excurrent, bryoides-type; laminal cells 1-stratose, distinct, smooth, ± bulging, firm-walled, elongate, 7-22 × 4-13 µm, increasing in size toward proximal part of leaf. Sexual condition rhizoautoicous; perigonia gemmiform, proximal to infertile and fertile stems. Sporophytes 1 per perichaetium. Seta to 12 mm. Capsule theca exserted, ± erect, radially symmetric to inclined, arcuate, bilaterally symmetic, 0.35-1.25 mm; peristome bryoides-type; operculum 0.25-0.3 µm. Calyptra cucullate, smooth, 0.5 mm. Spores 11-18 µm.

Plants very small, growing in dense tufts; fertile and sterile stems mixed in the same tufts. Fertile leafy stems ca. 1.5 mm long, 0.8 mm wide, with 3 (rarely) pairs of leaves; sterile leafy stems 1–4 mm long, 0.6–1.0 mm wide, with 4–16 pairs of leaves; axillary hyaline nodules weakly differentiated; central strand lacking. On fertile stems, upper and perichaetial leaves much longer than lower leaves, linear-lanceolate, 0.5–1.4 mm × 0.15–0.20 mm, narrowly acute at apex; leaves of sterile stems similar, lanceolate, 0.8–1.0 mm long, 0.1–0.2 mm wide, acute at apex; base of dorsal laminae wedge-shaped; vaginant laminae 1/2 –2/3 the leaf length; costa shortly excurrent; margins entire; limbidia 2–3 cells wide on apical laminae, 3–7 cells wide in vaginant laminae, 1–2 cells thick in cross- section; cells of apical and dorsal laminae quadrate to irregularly hexagonal, 7–16 µm long, thin-walled; cells at base of vaginant laminae longer, up to 21 µm long. Rhizautoicous. Male buds very small. Archegonia terminal, ca. 240 µm long. Setae 3.5–4.6 mm long, smooth; capsules cylindrical, erect, symmetrical; urns 0.45–0.60 mm long; peristome teeth ca. 0.2 mm long, 32 µm wide at base.

Distribution: China, India, Japan, and Africa.

Habitat: on rocks.

Fissidens milobakeri L. F. Koch

Fissidens saxatilis Tuz. & Nog., J. Jap. Bot. 24: 145. f. 1. 1949. Fissidens strictulus C. Müll., Nuovo Giorn. Bot. Ital., n. ser. 5: 159. 1898. Type. China: Shaanxi (Schen-si), Tui-kio-san (Taibai Shan), IX 1896, P. J. Giraldi s.n. (isotype FI). Fissidens subxiphioides Broth., Symb. Sin. 4: 9. 1929. Type. China: Yunnan, Li-jiang Co., 2900–3100 m, Handel-Mazzetti 6604 (holotype H).