Isothecium elegans Bridel, Bryol. Univ. 2: 356. 1827, based on Hypnum elegans Hooker, Musci Exot. 1: plate 9. 1818, not Bridel 1801; H. borrerianum Müller Hal.; Isopterygium elegans (Bridel) Lindberg; Plagiothecium elegans (Bridel) Schimper; P. elegans var.gracilens (Grout) H. A. Crum, Steere & L. E. Anderson; P. elegans var. schimperi (Juratzka & Milde) Limpricht; P. elegans var. terrestre (Lindberg) Rau & Hervey

Plants in thin to dense mats, dark green to yellowish. Stems 3.5 cm, 1-2.5 mm wide, complanate-foliate. Leaves erect-spreading or sometimes secund with apices pointing toward substrate, not upturned-homomallous, close to somewhat distant, lanceolate, ovate- or oblong-lanceolate, symmetric, smooth or weakly undulate, 0.3-2 × 0.2-0.7 mm; margins plane, serrulate to entire proximally, serrulate to strongly serrate distally; apex acuminate; costa double, strong; alar cells undifferentiated or quadrate to rectangular, 1-3 on margins; medial laminal cells 48-100 × 4-7 µm; distal cells sometimes minutely prorulose at distal ends on abaxial surface. Specialized asexual reproduction present as propagula clustered in leaf axils below stem apices, 0.5-1.5 mm, yellow to green, not twisted-vermiform, resembling parent plant but smaller, bearing reduced leaves from apex to base of stems. Sexual condition dioicous. Seta 1-2.5 cm. Capsule cernuous to pendulous, oblong-ovoid to ovoid, 1-2 mm; operculum conic to short-rostrate. Spores 7-12 µm.

Capsules mature spring-summer. Woods, acidic rock and soil, humus, base of trees, rotten logs; low to high elevations (0-2000 m); B.C., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Yukon; Ala., Alaska, Ark., Calif., Conn., Del., Ga., Idaho, Ill., Ind., Ky., Maine, Md., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., S.C., Tenn., Vt., Va., Wash., W. Va.; s South America (Argentina).

Pseudotaxiphyllum elegans is morphologically similar to 2. P. distichaceum. For distinctions, see discussion of that species.