Neckera breviseta Hooker & Wilson, J. Bot. (Hooker) 4: 419, plate 24, fig. A. 1842

Plants in thin mats, yellow-green. Stems to 5 cm, subpinnate, branches terete-foliate. Leaves erect to spreading, oblong-lanceolate, slightly plicate, 1.2-2 mm; margins plane, subentire proximally, ± serrulate distally; apex slender acuminate; ecostate or costa double, short; alar region ± abruptly differentiated, 1-stratose, not reaching costa. Sexual condition autoicous. Seta yellow, 0.5-1.5 cm. Capsule cylindric, to 1.4-2 mm; annulus 3- or 4-seriate, persistent; operculum bluntly short-rostrate; exostome teeth reddish, external surface densely papillose throughout, not perforate; endostome segments densely papillose. Spores 16-21 µm.

Bark at base of hardwood trees, logs, stumps, rock; low to moderate elevations; N.B., Nfld. and Labr. (Nfld.); Ga., Ill., Ind., Maine, Mass., N.J., N.Y., N.C., Ohio, Pa., Va., W.Va., Wis.

Entodon brevisetus is an uncommon but widely dispersed species recognizable by its terete-foliate plants with slenderly acuminate leaves. The setae are yellow and the exostome teeth are densely papillose throughout. The endostome is sometimes adherent to the exostome teeth.