Plants in dense mats, yellowish green, somewhat glossy. Stems to 30 × 1.5--3 mm, prostrate to ascending, pseudoparaphyllia foliose. Leaves imbricate to somewhat spreading, often somewhat falcate when dry, ovate to ovate-lanceolate, long-acuminate, smooth, distinctly but shortly decurrent, 1.5--3 × 0.4--0.6 mm, margins serrulate to entire; cell walls pitted at leaf base, sometimes pitted to leaf middle; median cells 33--85 × 4--7 μm; alar cells hyaline, abruptly inflated, rounded to oblong, 14--70 × 14--28 μm. Sexual condition dioicous. Seta yellowish brown, 1.1--1.5 cm. Capsule light brown, inclined, 2.5--3 × 0.3--0.5 mm, cylindric, slightly arcuate, when dry not or little contracted below mouth; operculum conic to conic apiculate, 0.3--0.4 mm. Spores 17--22 μm.

Capsules very rare, mature late summer. Tree trunks, rotten logs and stumps or humus over acidic cliffs; 0--90 m; B.C.; Alaska; Asia.

Herzogiella adscendens, previously included in the genus Campylium, is the most recent addition to Herzogiella (Z. Iwatsuki and W. B. Schofield 1973). It differs from the other North American Herzogiella species by its dioicous condition, serrulate to entire leaves, presence of foliose pseudoparaphyllia (sometimes difficult to find) and perichaetial leaves that are about twice as long as the other leaves.