Stems: creeping to more often arching-ascending, 1–3 mm wide across leafy stem, sympodial, rarely appearing monopodial in reduced arctic-alpine forms, regularly 2- or 3-pinnate; paraphyllia many, base multiseriate, branches 1- or 2-seriate. Stem: leaves tightly appressed on stipe to erect among branches, heteromallous, not crowded, oblong-ovate to ovate, lightly plicate, sometimes rugose in acumen, 1.6–3.2(–4) mm; base not decurrent; margins serrulate to nearly entire proximally, serrate to serrulate distally; apex abruptly acuminate, or occasionally rounded, obtuse, or abruptly acute; costa double, 1/4–1/2 leaf length, sometimes nearly ecostate; alar cells not differentiated; laminal cells occasionally minutely prorate. Branch: leaves ovate to elliptic-lanceolate. Capsule: inclined to pendent; operculum conic, obliquely long-rostrate; exostome teeth reticulate proximally; endostome segments broadly perforate, usually split into one large gaping perforation. North America, Eurasia, n Africa, Pacific Islands (New Zealand), Australia, cool temperate, boreal, and arctic regions.