Plants medium sized to rather large and robust, forming tufts or mats, light to dark green, yellowish-green to golden-brown. Primary stems short to long creeping, leaves scale-like or eroded; radiculose beneath stems. Secondary stems ascending to pendent or stiffly erect and dendroid or subfrondose, stipitate or not, when stipitate leaves triangular to ovate-triangular; irregularly to regularly pinnately branched, distal branch flagelliform or not; paraphyllia present or absent; pseudoparaphyllia foliose. Leaves crowded to somewhat distant, complanate or radially foliate, ovate- to oblong-lanceolate, oblong-lingulate, or cultriform, smooth, plicate or undulate, symmetric to strongly asymmetric, apex obtuse to acute, truncate or acuminate, base not or short decurrent on one side; margins plane to folded at base (usually along one side), entire or distally dentate, serrulate to serrate; costae single and 1/2-4/5 lamina length or short to somewhat long forked, occasionally absent; laminal cells smooth to occasionally papillose by projecting cell angles, apical cells short to elongate, median cells linear to fusiform or rhomboidal, and often vermicular, or rhomboidal to short hexagonal, walls entire or porose. Autoicous or dioicous. Perichaetia lateral; leaves usually sheathing, strongly differentiated, with or without linear leaf-like scales on vaginula. Setae short to elongate, smooth. Capsules immersed or short to long exserted, erect to horizontal or pendulous (Isodrepanium), urn ovoid to short cylindrical; stomata at urn base; annuli cells undifferentiated; opercula short to long rostrate, occasionally oblique; peristome double, exostome teeth 16, papillose or cross-striate below and distally papillose, rarely smooth; endostome basal membrane high to low, segments 16, narrow, weakly to rather strongly perforate, cilia absent or rudimentary to well developed. Calyptrae cucullate or mitrate (-campanulate), smooth and naked. Spores spherical, usually papillose.

Plantas medianas hasta bastante grandes y robustas, formando manojos o matas, verde pálidas hasta oscuras, verde amarillentas hasta pardo-doradas. Tallos primarios cortos hasta largos reptantes, hojas escuamiformes o erosionadas; radiculosos abajo. Tallos secundarios ascendentes hasta pendientes o rígidamente erectos y dendroides o subfrondosos, estipitados o no, cuando estipitados las hojas triangulares hasta ovado-triangulares; ramificaciones irregular hasta regularmente pinnadas, ramas distales flageladas o no; paráfilos presentes o no; pseudoparáfilos foliosos. Hojas agregadas hasta algo distantes, complanadas o radialmente foliosas, ovado- hasta oblongo-lanceoladas, oblongo-liguladas, o cultriformes, lisas, plegadas o unduladas, simétricas hasta marcadamente asimétricas, ápices obtusos hasta agudos, truncados o acuminados, base corto-decurrente sobre una lado o no; márgenes planos hasta plegados en la base (generalmente en un lado), enteros o distalmente dentados, serrulados hasta serrados; costa simple, alcanzando 1/2-4/5 de la longitud de la lámina o corto- hasta algo largo-bifurcada, ocasionalmente ausente; células de la lámina lisas hasta ocasionalmente papilosas, con papilas proyectándose en los ángulos de la célula, células apicales cortas hasta alargadas, células mediales lineales hasta fusiformes o rómbicas, a menudo vermiculares, o rómbicas hasta corto-hexagonales, paredes enteras o porosas. Autoicas o dioicas. Periquecios laterales; hojas generalmente envainadoras, marcadamente diferenciadas, con o sin escamas lineales foliformes sobre la vaginula. Setas cortas hasta alargadas, lisas. Cápsulas inmersas o cortas hasta largo-excertas, erectas hasta horizontales o péndulas (Isodrepanium), urna ovoide hasta corto cilíndrica; estomas en la  base de la urna; células del anillo indiferenciadas; opérculo corto- hasta largo-rostrado, ocasionalmente oblicuo; peristoma doble, exostoma con 16 dientes, papilosos o con estrías cruzadas en la base y distalmente papilosos, rara vez lisos; membrana basal del endostoma alta hasta baja, con 16 segmentos, angostos, débilmente hasta bastante marcadamente perforados, cilios ausentes o rudimentarios hasta bien desarrollados. Caliptra cuculada o mitrada (-campanulada), lisa y desnuda. Esporas esféricas, generalmente papilosas.

1. Leafy plants with secondary stems not stipitate … 2.

1. Leafy plants generally stipitate … 4.

2. Leaves cultriform, distal half strongly curved back … Isodrepanium

2. Leaves not cultriform, asymmetric and slightly arching … 3.

3. Leaves broadly ovate-lanceolate to -ligulate, apex acute to acuminate, costae short and forked … Neckera

3.. Leaves broadly lingulate, apex truncate, costae single, ca. 3/4 lamina length … Neckeropsis

4. Apical leaf cells usually rounded with angles projecting or not; secondary stem leaves small, to 1.4 mm long … Pinnatella

4. Apical leaf cells rhombic to fusiform, smooth or if papillose by projecting angles; secondary stem leaves mostly longer than 1.5 mm … 5.

5. Plants usually dull or dark green to blackish; costa strong, mostly subpercurrent; apical cells mostly short-rhombic … Thamnobryum

5. Plants usually glossy light yellowish-green to somewhat dark green; costa slender, mostly 1/2-3/4 lamina length; apical cells fusiform to long-rhomboidal … 6.

6. Plants lax and somewhat soft, often subpendent; branches terete-foliate … Porotrichodendron

6. Plants often rather stiffly erect, or if lax then leaves distant; branches mostly complanate-foliate … 7.

7. Leaf alar region differentiated, cells subquadrate, ± thick-walled, golden-brown … Porotrichopsis

7. Leaf alar region weakly or not differentiated, cells gradually differentiated, concolorous … Porotrichum