Plants very small to large, as scattered plants or deep, sometimes extensive, turfs. Stems 0.1-10 cm, , often bearing subfloral innovations below the gametangia. Leaves (with dorsal and lateral not differentiated), erect to spreading, narrowly lanceolate to ovate-lanceolate [rarely linear-lanceolate], 0.6-3.5 mm; base decurrent or not; margins plane (strongly revolute in P. cardotii and P. crudoides), finely serrate to serrulate near apex, rarely entire; apex acute (sometimes short-acuminate in P. melanodon); costa ending well before apex, subpercurrent, percurrent, or rarely short-excurrent; distal medial laminal cells elongate-hexagonal, rhombic, or linear-rhomboidal, sometimes narrowly vermicular; marginal cells undifferentiated or slightly narrower and longer than medial cells. Specialized asexual reproduction common, by spheric to ovoid rhizoidal tubers or axillary filiform to bulbiform gemmae. Sexual condition dioicous, paroicous, or rarely autoicous; perigonia and perichaetia terminal (perigonia rarely lateral in P. longibracteata); perigonial leaf apex acute to long-acuminate; perichaetial leaves same size as vegetative leaves or sometimes strongly differentiated, lanceolate to narrowly linear-lanceolate. Seta single (multiple in P. robertsonii), stramineous to orange-brown, straight or bent. Capsule inclined 0-180°, narrowly cylindric to broadly pyriform or urceolate, 1-6[-10] mm, neck sometimes 1+ times urn length; exothecial cells near mouth in 1-3+ rows, medial cell walls straight or sinuate; stomata superficial to immersed; annulus absent or present, revoluble; operculum convex, short-to long-conic, sometimes short-rostrate; peristome double [rarely absent], 4:2:4-6(-8); exostome white, pale yellow to brown, or sometimes dark reddish brown, teeth triangular to lanceolate, sometimes irregular [rarely reduced or absent], trabeculate or not, pitted basally, coarsely papillose distally (coarsely papillose throughout in P. crudoides); endostome basal membrane low to high, sometimes scarcely exceeding capsule rim, segments narrow to wide, strongly to weakly or scarcely keeled, rarely reduced to rudimentary projections, broadly to narrowly perforate or less often not, cilia absent or 1-3.
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