Streptopogon erythrodontus (Tayl.) Wils., Hooker’s J. Bot. Kew Garden Misc. 3: 51. 1851.
Barbula erythrodonata Tayl., London J. Bot. 5: 50. 1846. Protologue: Ecuador. On Pichincha, near Quito, Prof. William Jameson, (Dr. Greville’s Herbarium).
Streptopogon rutenbergii C. Müll., Abh. Naturwiss. Vereine Bremen 7: 207. 1881. Streptopogon erythrodontus var. rutenbergii (C. Müll.) Salm., Ann. Bot. (London) 17: 113. 1903. Protologue. Madagascar. Wald von Ambatondrazaka, 6 Decbr. 1877, in wenigen Individuen.
Streptopogon heterophyllus Herz., Biblioth. Bot. 87: 46. 1916. Protologue: Bolivia. An Bäumchen beim Asiento (Aracatal), ca. 3800 m, [Herzog] No. 2992 (JE); an Bäumen bei Samaipata (Ost-Cordillere) ca. 1700 m, [Herzog] No. 5125 (JE); an Bäumchen bei Altamachi, ca 3500 m, [Herzog] No. 3858 (JE).
Steptopogon matudianus Crum, Bryologist 55: 51. 1952. Protologue. Mexico. On the bark of an ash tree below El Puerto, above Acultzingo, Estadao de Veracruz, México, 7300 ft. elev., Aaron J. Sharp 689, September 13, 1944 (MICH), syn. nov.
Plants small to medium-sized, scattered or gregarious, dark-green, reddish green to reddish yellow, corticolous. Stems 10–30 mm high, irregularly branched, central strand absent, cortical cells thin-walled, hyaline, uniform throughout; rhizoids in dense clusters on lower parts of stem, densely branched, branches often at right-angles. Leaves 4–7 mm long, lanceolate, erect at base, more or less keeled, evenly spaced, erect, crispate and contorted when dry, wide-spreading when wet; apices acuminate, cuspidate to long-awned; margins sharply serrate, plane, bordered by several rows of long, narrow cells; costa excurrent as a toothed awn, ventral surface cells rectangular, smooth on both surfaces, guide cells and single (dorsal) stereid or substereid cells present, dorsal surface cells enlarged, ventral surface cells absent the guide cells ventrally exposed; upper cells rectangular to rhomboidal 30–70 x 10–24 μm, thin-walled, somewhat bulging near costa, smooth on both sides, marginal cells long, narrow, thick-walled in 2–3 rows, basal cells long-rectangular, thin-walled, bulging, smooth, 44–100 x 14–24 μm, alar cells not differentiated. Asexually reproducing by long uniseriate, marginal propagula. Autoicous. Setae 2–4 mm long, reddish yellow. Capsules cylindrical, erect, 2–4 mm long, smooth, yellowish brown; exothecial cells rhomboidal, thin-walled; stomata at base of capsule; opercula conical, 1.5 mm long; annuli adherent, 1–2 rows of non-vesiculose, thick-walled cells, adherent to operculum on dehiscence; peristome teeth 1–1.4 mm long, dark red, teeth filamentous, spiculose, twisted several turns, basal membrane short, red above, hyaline at base. Spores granular, 18–22 μm. Calyptrae campanulate, 2 mm long, lobed at base, roughened to hispid.