Sharpiella striatella (Bridel) Z. Iwatsuki
Plants in thin to dense mats, yellowish to dark-green, brownish green with age, glossy. Stems to 20 × 0.5--2 mm, ascending to erect, pseudoparaphyllia lacking. Leaves loosely imbricate to somewhat spreading, often squarrose, sometimes squarrose-recurved, usually straight at stem and branch apices, ovate to ovate-lanceolate, acuminate, smooth, distinctly decurrent, 0.6--2 × 0.3--0.8 mm; margins serrulate to serrate; cell walls pitted at leaf base and sometimes pitted to leaf middle or beyond; median cells 24--50 × 4--7 μm; alar cells hyaline or sometimes orange to red, abruptly inflated, rounded to oval, in 2--4 vertical rows of 4--6 cells, 14--65 × 14--24 μm. Sexual condition autoicous. Seta light brown to red, 0.9--2 cm. Capsule light brown, inclined to nearly erect, 1--2 × 0.3--0.5 mm, oblong to cylindric, slightly arcuate to straight, when dry not or little contracted below mouth; operculum conic to conic-apiculate, 0.3--0.4 mm. Spores 10--15 μm.
Capsules mature summer. Shaded soil and humus, often on acidic cliffs and rocks, rotten logs, stumps, bases of trees and exposed tree roots; 0--2000 m; Greenland; B.C., N.B., Nfld., N.S., Ont., P.E.I., Que.; Alaska, Conn., Ga., Ky., Maine, Md., Mass., Mich., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., Wash., W.Va., Wis.; Europe; Asia.
This species is recognized by the close, squarrose to squarrose-recurved leaves with 2--4 rows of abruptly inflated, hyaline or orange to red, decurrent cells extending 4--6 cells down the stem. Herzogiella striatella has a disjunct distribution in North America, occurring commonly in the eastern third of the continent and more rarely in the western part in Alaska, British Columbia, and Washington. Herzogiella striatella may have a closer relationship to H. cylindricarpa (Cardot) Z. Iwatsuki of Mexico, Central and South America, and Africa than to the other North American species as revealed by a scanning electron microscope study of the spore ornamentation (R. R. Ireland 1990). Alabama report by R. R. Ireland (1991) is an error.