Plants small, forming loose to ± dense mats, light to dark green. Stems and branches loosely creeping to subascending, 1-3 pinnately branched; central strand present; paraphylla few and scattered along stems, often absent on branches, unbranched or little-branched, weakly papillose. Leaves of stems and branches little differentiated in size and shape, ovate to cordate- or triangular-short to long acuminate, apex erect or subsquarrose, usually bifid or notched; margins plane to recurved below, entire or crenulate-dentate by projecting papillae; costae single, stem leaf costa mostly ending below or extending into acumen; laminal cells isodiametric, pluripapillose, papillae projecting on both sides of lamina, thick-walled. Autoicous. Perichaetia lateral; leaves elongate, ovate-triangular to -lanceolate, apex short to more commonly long acuminate; margins entire to long ciliate. Setae elongate, papillose, rarely smooth. Capsules inclined, pendent or erect to suberect, urn short to somewhat long ovoid or ovoid-cylindrical, slightly curved or not; annuli in 2-3 rows; opercula conic to conic short to long rostrate, oblique; peristome double, exostome teeth 16, cross-striate, papillose distally; endostome basal membrane high, segments 16, keeled, cilia1-3(4). Calyptrae cucullate, smooth and naked. Spores spherical, appearing smooth to lightly papillose.

Plantas pequeñas, formando matas laxas hasta ± densas, verde claras hasta oscuras. Tallos y ramas laxamente reptantes a subascendentes, ramas 1- 3 pinnadas; cordón central presente; pocos paráfilos, esparcidos a lo largo de los tallos, a menudo ausentes en las ramas, sin ramificar o poco ramificados, débilmente papilosos. Hojas de los tallos y ramas poco diferenciadas en tamaño y forma, ovadas hasta -cordadas o corto-triangulares hasta largo-acuminadas, ápices erectos o subescuarrosos, generalmente bífidos o con una escotadura; márgenes planos a recurvados en la porción inferior, enteros o crenulado-dentados por las proyecciones de las papilas; costa simple, costa de las hojas del tallo generalmente terminando debajo o extendiéndose hasta el acumen; células de la lámina isodiamétricas, pluripapilosas, rara vez unipapilosas, papilas proyectándose en ambos lados de la lámina, con paredes gruesas. Autoicas. Periquecios laterales; hojas alargadas, ovado-triangulares hasta -lanceoladas, ápices cortos a más comúnmente largo-acuminados; márgenes enteros hasta largo-ciliados. Setas alargadas, papilosas, raras veces lisas. Cápsulas inclinadas, pendientes o erectas hasta suberectas, urna corta hasta algo largo-ovoide u ovoide-cilíndrica, escasamente curvadas o no; anillo en 2-3 filas; opérculo cónico, cónico-corto hasta largo-rostrado, oblicuo; peristoma doble, exostoma con 16 dientes, con estrías cruzadas, distalmente papilosos; membrana basal del endostoma alta, con 16 segmentos, carinados, -3(4) cilios. Caliptra cuculada, lisa y desnuda. Esporas esféricas, de apariencia lisa hasta finamente papilosa.

1. Leaf cells unipapillose … P. muricatulum

1. Leaf cells pluripapillose … 2

2. Capsules erect to suberect; setae smooth or slightly papillose (roughened) below urn … P. leptocladum

2. Capsules horizontal to pendent; setae papilllose or smooth (P. involvens) … 3.

3. Plants 1-pinnate; branch leaves incurved when dry; oblong-lanceolate, nearly the same size as stem leaves; paraphyllia few on stem … P. involvens

3. Plants 2-3-pinnate; branch leaves not or slightly incurved when dry; ovate, distinctly smaller than the stem leaves; paraphyllia usually numerous on stem … 4.

4. Paraphyllia 2-3-celled, cells ca. 2 times longer than wide; plants usually weakly 2-pinnate; setae smooth throughout; perichaetial leaves lacking cilia along margin … P. involvens

4. Paraphyllia 2-8-celled, cells mostly quadrate; plants regularly 2(3)-pinnate; setae roughened (papillose) throughout; perichaetial leaves ciliate or lacking cilia along margins … 5.

5. Paraphyllia almost all 3-5-celled; branch leaves laxly disposed and spreading, branches readily observable; perichaetial leaves not ciliate or cilia few, short and erect … P. scabrosulum

5. Paraphyllia 3-5- but some 6-8-celled; branch leaves appressed, branches not readily observable; perichaetial leaves ciliate, cilia long, flexuose … P. schistocalyx