Plants in erect, loose to dense tufts, green, yellowish or brownish, shiny or dull. Stems 1-2(-6) cm, erect-spreading, simple branches, sparsely radiculose near apex. Leaves lanceolate, gradually subulate, erect-spreading, sometimes falcate-secund; margins erect, entire, to serrulate near the tips; costa mostly excurrent, narrow, stereids poorly differentiated from median guide cells; distal laminal cells linear to subquadrate, smooth or slightly mammillose; basal laminal cells elongate, smooth, sometimes porose, alar cells usually brown and well differentiated. Sexual condition cladautoicous or gonioautoicous. Pericheatial leaves with a sheathing base. Seta solitary, 7-16 mm, erect, yellow turning red with age. Capsule suberect, curved, cylindric, smooth to furrowed when dry, indistinctly strumose; operculum obliquely rostrate; peristome single, of 16, teeth, divided halfway into two segments, papillose to vertically striolate or pitted striolate, red-brown. Calyptrae cucullate, occasionally rough at apex. Spores spheric, 14-24 µm, finely roughened, yellow to greenish yellow.

A northern and alpine genus, Kiaeria occurs on siliceous rock or soil and is recognized by its medium-sized, Dicranum-like habit, with poorly differentiated stereid and guide cells. It may be confused with several other tufted acrocarps of similar size, such as Dicranoweisia, which has crisped, contorted leaves when dry; Oncophorus, which has distinctly strumose capsules and occurs on wood or humus; or Dicranella, which differs in its obliquely grooved capsules, and narrow hairlike leaves. The species in Kiaeria are difficult to distinguish, but some characters are useful for tentative field identification, including presence of grooves on capsule, leaf luster, growth form, and habitat.