Keys to the Subclasses and Families of Mosses of the Tropical Andes
The following keys are intended to assist in the identification of mosses from the Tropical Andes. The keys are designed to stress gametophytic features whenever possible. Sporophytes are often not present in collected material, and, in some cases, not known in the Neotropics or elsewhere. For this reason, and because a number of families exhibit considerable variation, families are often keyed out in more than one place. The keys often emphasize salient features of families with primary emphasis on gametophytic characters, secondarily on sporophytic characters, and lastly on habitat or geography. In using the keys, one normally follows the lead that best fits the two alternative choices given. When one reaches a point in the key in which neither lead appears appropriate, one then should follow both, hopefully ending with two alternative families. Both should then be compared carefully with the descriptions, keys to genera and illustrations (in prep.). If neither alternative appears appropriate, then one must backtrack in the keys to find where the problem of interpreting a particular character exists. In any case, one should read carefully the family description, keeping in mind the variation exhibited by that family (this applies equally to genera).
Key to the subclasses
1. Plants typical of boggy or marshy sites, whitish; branches spirally arranged in fascicles; laminal cells of stem and branch leaves alternating between leucocyst (hyaline cells) and chlorocyst (green) cells; capsules globose, supported by a pseudopodium … Sphagnopsida (Sphagnaceae)
1. Plants mostly of drier sites, mostly green, yellow or brown; laminal cells uniformly similar with chlorophyll, or chlorophyll cells layered between hyaline cells above and below; not alternating between hyaline and green cells; capsules variously shaped, supported by a pseudopodium or seta … 2.
2. Plants small, deep dark red or blackish, largely restricted to open high elevations, in páramo and puna; capsules supported by a pseudopodium, opening by 4 (division throughout) or 8 (distal tip) slits or valves … Andreaeaopsida (Andreaeaceae)
2. Plants small to medium sized or robust, present in all environments; capsules stegocarpic, supported by a seta, generally with a peristome and operculum … 3.
3. Leaves bearing rows of lamellae on distal upper surface; capsules with a single series of peristome teeth, teeth 16, 32, or 64, distally attached to a circular membrane (epiphragm) … Polytrichopsida (Polytrichaceae)
3. Leaves lacking rows of lamellae, or very rarely so (see Grimmiaceae, Pottiaceae); capsules either with a peristome in a single series with 16 teeth, or a double series with the outer series of 16 teeth (exostome), and inner series with a basal membrane bearing 16 segments and cilia (endostome), in a number of cases the peristome is reduced … Bryopsida
General key to the families
1. Plants whitish, laminal cells alternating or layered between leucocyst and chlorocyst cells … Section 1
1. Plants variously green, yellow to golden or brown to blackish; laminal cells uniform, neither layered or alternating between leucocyst and chlorocyst cells walls … 2.
2. Upper distal surface of leaf with discontinuous or continuous rows of lamellae … Section 2
2. Upper distal surface lacking lamellae … 3.
3. Plants acrocarpous; stems erect or occasionally spreading, solitary or in short to long tufts or cushions; sporophytes terminal on stems or branched innovations; peristome single (a single series of teeth 16 or divided into 32 narrow segments) or double (two series, outer series of 16 teeth, inner series often with 16 segments and often cilia atop a short to tall membrane) … 4.
3. Plants pleurocarpous, stems creeping, spreading, or pendent, frondose or dendroid from a conspicuous or inconspicuous creeping primary stems; sporophytes lateral on stems; peristome double or variously reduced … 6.
4. Leaves arranged in 2 ranks (distichous) or 4 ranks (but appearing 2-ranked) … Section 3
4. Leaves arranged in 3 or more rows … 5.
5. Laminal cells papillose or mammillose … Section 4
5. Laminal cells smooth … Section 5
6. Leaf costa absent, short and forked, or elongate and double … 7.
6. Leaf costa single … 9.
7. Leaves distinctly 2-ranked, usually strongly folded … Section 6
7. Leaves in 3 or more ranks, when complanate often with lateral asymmetric leaves (occasionally partially folded on one side) and median symmetric leaves … 8.
8. Leaves ecostate (most leaves lacking a costa, a few leaves may have a very weak costa) … Section 7
8. Leaves with costa, short and forked or elongate and double … Section 8
9. Leaves strongly dimorphic, upper or lower leaves on stems smaller and differing in shape than larger lateral leaves … Section 9
9. Leaves monomorphic, usually differing if at all between smaller branch leaves or lateral leaves asymmetric and median leaves symmetric … 10.
10. Laminal cells mammillose or papillose … Section 10
10. Laminal cells smooth … Section 11
Section 1. Plants whitish, laminal cells alternating or layered between leucocyst and chlorocyst cells.
Plants whitish, occasionally reddish or purplish tinged; laminal cells differentiated, alternating or layered between hyaline cells (leucocysts) and green cells (chlorocysts).
1. Plants typically of boggy or seepy sites; forming a compact head of clustered short branches (capitulum), below capitulum stems with short to elongate fasciculate branches; leaves of stem and branch dimorphic; in cross-section lamina unistratose, cells alternating between chlorocysts and leucocysts … Sphagnaceae
1. Plants of most to semi-dry sites, often lignicolous or epiphytic; stem and branch leaves monomorphic, mostly evenly distributed along stems; in cross-section lamina bi- to multistratose, chlorocysts layered between 1 or more layers of leucocysts above and below … 2.
2. Leaves faintly single costate, chlorocysts cells clustered near center on abaxial (back) of leaf … Calymperaceae (Leucophanes)
2. Leaves appearing ecostate; chlorocysts cells evenly distributed in a single row between leucocyst cells, not forming a cluster of cells toward the center … 3.
3. Leaves above not channeled, flat or plano-convex in cross-section; base often ovate to obovate … Octoblepharaceae
3. Leaves above channeled, margins somewhat involute, weakly to strongly concave in cross-section … Leucobryaceae
Section 2. Upper distal surface of leaves with rows of lamellae or short filaments.
1. Lamellae in long continuous rows, occasionally rows few or discontinuous; peristome teeth 16, 32 or 64, entire, usually with tips of teeth attached to an epiphragm … Polytrichaceae
1. Lamellae forming short rows or occurring as short filaments scattered over surface; peristome of 16 teeth, often perforate or divided … 2.
2. Distal upper surface covered by filaments, often papillose, if with lamellae then leaves ovate with margins plane; calyptra cucullate … Pottiaceae p.p.
2. Distal upper surface covered by rows of lamellae, with leaf margins erect to incurved; calyptra campanulate, lobed at base … Grimmiaceae (Aligrimmia - Peru)
Plants acrocarpous, stems mostly erect or occasionally spreading, solitary or in short to tall loose or dense tufts; sporophytes terminal on stems or branched innovations; peristome single or double, rarely absent.
Section 3. Plants acrocarpous. Leaves arranged in 2 ranks (distichous) or in 4 ranks but appearing 2-ranked.
1. Leaf costa long excurrent, 2-3 times longer than lamina length; lower and basal cells linear-rectangular; confined to páramo and puna … Ditrichaceae (Distichium)
1. Leaf costa subpercurrent to short excurrent (rarely long excurrent), lower and basal cells quadrate to rectangular; lowland to high montane, rarely in páramo/puna … 2.
2. Leaves exhibiting an extended dorsal and ventral lamina from a sheath-like leaf base (vaginant laminae) … 3.
2. Leaves lacking an extended dorsal and ventral lamina from a sheath-like base … 4.
3. Plants solitary or forming tufts, erect to suberect; marginal border cells of leaf linear or oblong-linear, usually thick-walled; capsules long exserted; widespread at all elevations … Fissidentaceae
3. Plants forming mats, procumbent (pleurocarpous); marginal border cells very large, subrectangular, thin-walled; capsules immersed; Ecuador, montane … Sorapillaceae
4. Leaves strongly asymmetric; costa closer to one side of lamina; gemmae commonly clustered on denuded stem tips; wet lowlands … Phyllodrepaniaceae
4. Leaves ± symmetric or weakly asymmetric; costa longitudinally centered on leaf; gemmae if present then in leaf axils; mostly montane or subalpine … 5.
5. Leaves folded, conduplicate; laminal cells pluripapillose … Eustichiaceae
5. Leaves flat, not folded; laminal cells smooth … 6.
6. Stems spreading or creeping; leaves elliptical, bordered … Mniaceae (Plagiomnium)
6. Stems erect; leaves ovate, lacking a bordered … Rhizogoniaceae (Rhizogonium)
Section 4. Plants acrocarpous. Leaves in 3 or more rows. Laminal cells papillose or mammillose (cells often isodiametric or shortly elongate).
1. Basal portion of leaf exhibiting a cancellinae (enlarged clear cells), strongly differentiated from basal margin and distal cells; marginal or intramarginal border often present; laminal cells above isodiametric, gemmae nearly always present on leaves, particularly leaf tips; plants mostly epiphytic … Calymperaceae
1. Basal portion of leaf lacking a cancellinae (see Kingiobryum etc. in páramo), cells either similar to distal cells or gradually differentiated toward base, if differentiated then leaf border lacking; gemmae absent from leaves … 2.
2. Leaves ecostate; mostly on rocks … 3.
2. Leaves costate; on various substrate including rocks … 4.
3. Leaf margins plane; laminal cells unipapillose on back; plants small, deep dark red or blackish, in páramo and puna; capsules opening by 4 (division throughout) or 8 (distal tip) slits or valves … Andreaeaceae p.p.
3. Leaf margins recurved; laminal cells 1-several papillose, papillae in a row; plants medium sized, dark green to brown, or grayish; mid montane to páramo or puna; capsules operculate, lacking a peristome … Hedwigiaceae
4. Leaves completely to partially bistratose distally … 5.
4. Leaves unistratose or only partially bistratose, particularly restricted to margins … 8.
5. Peristome teeth of 16 teeth in 8 pairs; leaves spathulate, apex acute to apiculate … Rhachitheciaceae p.p.
5. Peristome teeth of 16 unpaired teeth; leaves mostly ovate-lanceolate to lanceolate, if spathulate then costa excurrent … 6.
6. Laminal cells subquadrate to short rectangular, appearing bipapillose … Ditrichaceae p. p.
6. Laminal cells rounded, mammillose … 7.
7. Leaf margins uni-, bi- or tristratose; perichaetial leaf costa long excurrent with distal lamina erose or fimbriate; sporophytes immersed; seta short; capsules strongly asymmetric, obliquely and broadly ovoid below, narrow toward mouth; peristome double; plants usually found on soil … Diphysciaceae
7. Leaf margins bistratose, sometimes incomplete below; perichaetial leaf costae subpercurrent; sporophytes exserted; seta elongate; capsules symmetric; peristome single; plants exclusively found on rocks … Grimmiaceae p.p.
8. Laminal cells stellate, unipapillose, papillae over cell lumen; basal cells inflated; leaf margins recurved nearly throughout; distal stems naked with a few highly reduced leaves; plants of marshes and bogs at high elevations … Aulacomniaceae
8. Laminal cells not stellate, uni- to pluripapillose; basal cells not conspicuously inflated; lacking specialized distal branches or stems (sometimes with deciduous leaves); plants mostly of semi-wet or dry sites … 9.
9. Laminal cells narrowly to somewhat broadly rectangular with projecting papillae at cell ends (rarely single over cell lumen); leaf margins often coarsely toothed, teeth single or more often double; capsules subglobose, inclined or if erect then immersed … Bartramiaceae
9. Laminal cells mostly isodiametric or short rectangular; papillae mostly over cell lumina or cells mammillose; leaf margins entire, crenulate or a few teeth at apex; capsules ovoid to cylindrical … 10.
10. Laminal cells often bipapillose; capsules immersed to shortly exserted; peristome double or reduced; calyptra campanulate, plicate or not, hairy or naked; epiphytic or rarely on rocks … Orthotrichaceae p.p.
10. Laminal cells uni- or pluripapillose, or mammillose; capsules mostly long, rarely short exserted; calyptra cucullate or if campanulate then long cylindrical, smooth; mostly terrestrial, occasionally epiphytic … 11.
11. Leaves bordered by few to several rows of hyaline cells, border extending 1/3 from base to near apex; laminal cells uni-, bi- or pluripapillose; alar cells well differentiated … Dicranaceae p. p.
11. Leaves lacking a border; cells variously ornamented; alar cell undifferentiated …12.
12. Leaves differentiated, base clasping, limb spreading; plants of wet or moist sites …13.
12. Leaves undifferentiated, or if so, then base not clasping stem or if clasping upper laminal cells pluripapillose …14.
13. Laminal cells subquadrate, mammillose; costa percurrent … Ditrichaceae p.p.
13. Laminal cells short-rectangular, rounded, papillae projecting at cell ends; costa short excurrent … Dicranaceae p.p.
14. Leaf costa in cross-section little differentiated, well developed stereid band lacking … 15.
14. Leaf costa in cross-section usually well developed, stereid band present, only below guide cells or both above and below … 17.
15. Laminal cells mammillose or weakly unipapillose, cells crowded, little space between cell lumens … Dicranaceae p. p.
15. Laminal cells pluripapillose, cells widely spaced, or if crowded, papillae extending between cell lumens …16.
16. Leaves spathulate or if narrowly oblong-lanceolate then hyaline basal cells extending upward along margin a short distance; peristome single, teeth 16 in 8 pairs … Rhachitheciaceae p.p.
16. Leaves narrowly lanceolate to oblong- or ovate-lanceolate, basal cells uniform across; peristome double or variously reduced, teeth 16 separated or in 8 pairs … Orthotrichaceae p.p.
17. Calyptrae long cylindrical-campanulate; leaves oblong-elliptic to -obovate, laminal cells coarsely pluripapillose, papillae usually branched; restricted to very high elevations (zacatonal, páramo or puna) … Encalyptaceae
17. Calyptra cucullate; leaves of various shapes; laminal cells uni- to pluripapillose, simple or branched; plants found in all zones … Pottiaceae p.p.
Section 5. Plants acrocarpous. Leaves in 3 or more rows, ranked or not. Laminal cells smooth.
1. Plants minute, ephemeral or not; leaves costate or ecostate, capsules cleistocarpous or gymnostomous, mostly immersed … 2.
1. Plants conspicuous, mostly medium sized to large, not ephemeral; leaves costate; capsules stegocarpous or rarely gymnostomous, mostly long exserted … 7.
2. Laminal cell walls firm, mostly rectangular to subquadrate …3.
2. Laminal cell walls lax, short- to long-rhomboidal or hexagonal-rhomboidal … 6.
3. Leaves oblong to obovate or orbicular, margins entire; annulus well developed … Rhachitheciaceae p.p.
3. Leaves mostly lanceolate, if obovate then distal leaf margins usually crenulate or weakly serrulate; annulus absent or well developed … 4.
4. Spores very large, few … Archidiaceae*
4. Spores small, numerous … 5.
5. Capsules with an elongate neck, often half or more the length of capsule, stomata often numerous in neck region … Bruchiaceae p.p.
5. Capsules with an inconspicuous neck or neck lacking, stomata few or absent … Ditrichaceae p.p.
6. Stems fleshy, partially subterranean; capsules wrinkled or warty, if smooth then exserted and leaves ecostate … Gigaspermaceae
6. Stems from a persistent protonema, not subterranean; capsules smooth or weakly bulging-mammillose, immersed … Ephemeraceae
7. Laminal cells narrowly rectangular and strongly sinuose throughout except at basal margin; plants found exclusively on rocks … Grimmiaceae (Racomitrium)
7. Laminal cells not sinuose throughout, walls entire, or if sinuose not strongly so and restricted in distribution, not throughout; plants found on various substrates including rocks … 8.
8. Leaf margins bordered, border extending to apex or ending somewhat below, adjacent inner laminal cells large, often hexagonal-elongate to broadly fusiform or rhomboidal … 9.
8. Leaf margins lacking a border, or if bordered then confined to leaf base; marginal cells similar to or only slightly differentiated from inner laminal cells … 12.
9. Laminal cells subquadrate and rounded to oblong-oval, distally obliquely arranged … Mniaceae p.p.
9. Laminal cells rhombic to elongate-hexagonal, not obliquely arranged … 10.
10. Leaf border consisting of long linear cells; capsules often inclined to pendulous … Bryaceae p.p.
10. Leaf border consisting of large, rectangular to fusiform cells; capsules erect, if inclined or subpendulous then seta hygroscopic … 11.
11. Capsules with a conspicuously modified, enlarged neck, often inflated or larger than urn; peristome single, 16 teeth united in pairs, or teeth 8, often recurved when dry; plants usually epiphytic, on dung or decaying plant material … Splachnaceae p.p.
11. Capsules with an inconspicuous or narrowed neck; peristome absent, single and represented by an exostome of 16 teeth, or double, teeth incurved when wet; plants mostly on soil … Funariaceae
12. Alar cells differentiated, quadrate to oblong or oval, often dark colored, yellow to red … 13.
12. Alar cells undifferentiated … 14.
13. Alar cells dark red; low, somewhat irregular membrane formed around and external to peristome; plants on rocks associated with streams, mostly at high elevations … Seligeriaceae p.p.
13. Alar cells often reddish-brown or golden; low, external membrane lacking; plants on various substrates and low to high elevations … Dicranaceae p.p.
14. Leaves appearing 3-ranked; seta conspicuously elongate (to 10 cm long or more); exostome reduced, endostome well developed; plants of mid to high elevations in boggy sites … Meesiaceae
14. Leaves spirally arranged, or more than 3-ranked; seta usually shorter; peristome various; plants either of drier sites or aquatic, rarely of boggy sites … 15.
15. Laminal cells distally linear-oblong or -fusiform and flexuous or not; capsules inclined to more often pendulous; peristome double, endostomial cilia often present, or represented by only an hyaline endostome with a low membrane … Bryaceae p.p.
15. Laminal cells isodiametric to short or long rectangular; capsules mostly erect to inclined; peristome single or double (Rhizogoniaceae) … 16.
16. Laminal cells above base isodiametric, small, thick-walled; plants often dark green, reddish-brown or blackish … 17.
16. Laminal cells often short to long rectangular, or distally grading into subquadrate cells, walls thin to rather thick-walled; plant mostly light to dark green … 19.
17. Costa in cross-section generally well developed, stereids above and below guide cells or only below, upper and lower epidermal cells differentiated or not; capsules often long exserted; peristome teeth often divided into 32 filaments; plants on soil or rocks, dry or wet sites, at all elevations … Pottiaceae p.p.
17. Costa in cross-section little or not differentiated; capsules short exserted or immersed, 4-valved or with peristome teeth perforate or divided only distally; plants confined to rocks and at very high elevations (páramo or puna) … 18.
18. Capsules 4-valved (peristome and operculum lacking); leaves strongly subulate from an ovate base or ovate with a very broad, diffuse costa to ca. 1/2 lamina length … Andreaeaceae p. p.
18. Capsules with peristome, teeth often perforate or divided above; leaves percurrent to excurrent as a hyaline awn … Grimmiaceae p.p.
19. Leaves elliptic, obovate spathulate, obtuse to rounded; peristome either with 16 teeth in 8 pairs or exostome extremely reduced … 20.
19. Leaves mostly ovate-lanceolate to narrowly lanceolate; margins entire to serrate; peristome with teeth when present not paired nor with exostome extremely reduced … 22.
20. Leaves mostly 2 mm long or more; capsules with a modified, enlarged neck, often inflated or larger/long than urn … Splachnaceae p.p.
20. Leaves mostly 1.2 mm long or less; capsules lacking a modified neck … 21.
21. Leaves obovate to elliptic, leaf apices not apiculate; perichaetial leaves similar to stem leaves, not long sheathing; capsules smooth … Splachnobryaceae
21. Leaves obovate to spathulate, leaf apices apiculate (most leaves); perichaetial leaves strongly differentiaed from stem leaves, long sheathing; capsules 8-ribbed … Rhachitheciaceae p.p.
22. Capsule neck elongate, 1.5-3 times longer than urn, stomata numerous in neck region; peristome absent or single (vertically striate below); costa subpercurrent; plants of disturbed sties, rather uncommon … Bruchiaceae
22. Capsule neck distinctly shorter than urn, or absent; peristome double or single (and often divided above); costa subpercurrent to excurrent; plants of various habitats … 23.
23. Perichaetia at mid stem or base; leaf margins bistratose and doubly toothed, if singly toothed then distal stem tips with cylindrical, papillose gemmae; plants epiphytic or terrestrial … Rhizogoniaceae p.p.
23. Perichaetia terminal on stems; lacking the above combinations of characters; plants on soil or rocks … 24.
24. Capsules ribbed; annulus compound, exceeding or nearly so the length of the peristome; leaves setaceous from an ovate base; plants rare … Seligeriaceae p.p.
24. Plants lacking the above combination of characters … 25.
25. Peristome teeth terete, often divided to near base, into 32 filaments … Ditrichaceae p.p.
25. Peristome teeth flat below, entire or divided above … Dicranaceae p.p.
Plants “pleurocarpous”; stems creeping, spreading, forming mats, or pendent, frondose or dendroid, often forming tufts, from a creeping primary stem; sporophytes lateral on stems; peristome double or variously reduced, rarely absent.
Section 6. Plants pleurocarpous. Leaves 2-ranked, strongly folded throughout or with sheath-like base.
1. Leaves exhibiting an extended dorsal and ventral lamina from a sheath-like leaf base (vaginant laminae); margins bordered, cells very large, subrectangular, thin-walled; capsules immersed; plants rare, only known from the type locality in Ecuador … Sorapillaceae
1. Leaves strongly folded, conduplicate, lacking a dorsal and ventral lamina; marginal border lacking; capsules shortly to fully exserted; plants common, throughout the Tropical Andes … 2.
2. Leaves to 1.5 mm long; apex mostly mucronate and reflexed; laminal cells entire, not porose … Catagoniaceae
2. Leaves 3 mm or more long; apices truncate or erect apiculate; laminal cells porose … Phyllogoniaceae
Section 7. Plants pleurocarpous. Leaves ecostate.
1. Plants aquatic, attached to rocks in streams or epiphytic in inundated lowlands; capsules immersed … 2.
1. Plants terrestrial, on soil, rocks, logs or epiphytic, if aquatic then alar cells inflated; capsules mostly exserted … 3.
2. Leaves mostly distant, crowded only at stem or branch tips, oblanceolate to obovate or elliptical; plants confined to lowlands … Hydropogonaceae
2. Leaves mostly crowded, lanceolate; plants confined to montane habitats or páramo … Fontinalaceae
3. Leaves broadly ovate, acute to piliferous, narrowly bordered, border differentiated in color, often dark red; laminal cells appearing finely pluripapillose, papillae minute and numerous over and between cells … Rhacocarpaceae
3. Leaves variously shaped, acuminate, acute, or obtuse rounded; laminal cells smooth or if papillose, papillae single or few over cell lumina …4.
4. Alar cells inflated, oval to oblong, mostly thick-walled, porose or not, often dark yellow or golden-red; laminal cells smooth or papillose, papillae over cell lumina … Sematophyllaceae p. p.
4. Alar cells absent or if present, then not inflated or oval, mostly subquadrate or oblate and quadrate- to short oblong-rounded … 5.
5. Leaf apex narrowly long acuminate … Leucomiaceae
5. Leaf apex broadly acute or if acuminate then laminal cells rhomboidal to fusiform-rounded and thick-walled … 6.
6. Leaves short ovate-lanceolate, to 0.7 mm long; laminal cells on back projecting at distal angles; alar cells equally distributed on either side of leaf base, mostly quadrate; plants forming mats … Myriniaceae p.p.
6. Leaves variously shaped, ovate-lanceolate, ovate to oblong, mostly greater than 1 mm long; laminal cells smooth, or occasionally on back projecting at distal angles; alar cells lacking or equally or unequally distributed on either side of leaf base, quadrate to oblong; plants forming mats, dendroid or pendent … 7.
7. Stems complanate foliate, lateral leaves slightly asymmetric or not … 8.
7. Stems terete foliate … 10.
8. Leaf margins finely bifid toothed; gemmae clustered beneath stems or on specialized terminal branches; epiphytic or epiphyllous … Pilotrichaceae (Crossomitrium)
8. Leaf margins entire to subentire; gemmae absent or if present on leaf tips; epiphytic on base trunk of trees, logs or soil … 9.
9. Alar cells well differentiated, unequally distributed with cells on one side more numerous; upper laminal cells linear; gemmae absent; moist to wet lowlands … Stereophyllaceae p.p.
9. Alar cells undifferentiated; upper laminal cells large, elongate-hexagonal; gemmae few on leaf tips and distal margins; montane forests … Hookeriaceae
10. Leaf margins plane distally; laminal cells obliquely arranged above, transversely toward base or not; median and upper cells rhomboidal to fusiform-rounded, porose or not … 11.
10. Leaf margins strongly incurved distally; laminal cells longitudinally arranged, linear, mostly porose … 12.
11. Leaves broadly lanceolate and plicate, or ovate and smooth, short acuminate; capsules exserted … Leucodontaceae
11. Leaves broadly ovate to suborbiculate, smooth, broadly acute, or if acuminate then tip hyaline; capsules immersed … Erpodiaceae
12. Plants dendroid, or subpendent and rather stiff; gemmae commonly present in leaf axils … Pteryobryaceae p.p.
12. Plants pendent or forming loose, spreading mats; gemmae absent … Meteoriaceae p.p.
Section 8. Plants pleurocarpous. Leaves costate; costae short and forked or double and elongate (often 1/2 or more than lamina length).
1. Leaves strongly cordate-auriculate; paraphyllia present, several branched … Hylocomiaceae p.p.
1. Leaves not cordate-auriculate, if auriculate only weakly so; paraphyllia absent or if present then linear, unbranched … 2.
2. Leaf costa double and elongate, often 1/2 or more the lamina length … Pilotrichaceae p.p.
2. Leaf costa mostly short and forked, mostly less than 1/2 the lamina length … 3.
3. Leaves complanate … 4.
3. Leaves teretely foliate, falcate-secund or not … 9.
4. Leaf margins bordered by few to several rows of narrow cells, inner cells large, rhomboidal to hexagonal; costa often indistinct or distally forked from a short single costa; seta papillose and ciliate distally … Daltoniaceae p.p.
4. Leaf margins lacking a border, occasionally cells of lamina progressively narrowed toward margin … 5.
5. Leaves ovate-oblong to oblong-lingulate, often undulate; apices mostly broadly acute to obtuse; capsules immersed to shortly exserted … Neckeraceae p.p.
5. Leaves mostly ovate to ovate-lanceolate, smooth; apices mostly acute to long acuminate; capsules exserted … 6.
6. Alar cells numerous, extending along leaf margin 1/5-1/3 … 7.
6. Alar cells few to several, rarely extending more than a few cells along margin; capsules erect to horizontal … 8.
7. Laminal cells smooth; capsules erect … Entodontaceae p.p.
7. Laminal cells papillose at cell angles; capsules inclined … Pterigynandraceae
8. Distal branches flagellate and readily deciduous; seta distally roughened to papillose; urn spinose … Symphodontaceae
8. Distal branches not flagellate, if so not readily deciduous; seta smooth; capsules lacking ornamentation … 8.
9. Leaves weakly serrulate to subentire distally, short to long decurrent; capsules suberect to horizontal, cylindrical … Plagiotheciaceae
9. Leaves often serrulate to serrate throughout, not or weakly decurrent; capsules ovoid and horizontal to subpendent or cylindrical and erect … Hypnaceae p.p.
10. Leaves falcate-secund or branches and stems distally curved or curled … 11.
10. Leaves mostly erect to spreading, not falcate-secund, branches and stems not curved … 12.
11. Alar cells quadrate to short rectangular, moderately thick-walled, concolorous or yellow to golden, or cells inflated and hyaline, thin-walled; exothecial cell walls of urn mostly evenly thickened; operculum conic-apiculate to -short rostrate … Hypnaceae p.p.
11. Alar cells inflated, thick-walled, often golden-red, supra-alar cells often present, subquadrate; costa weakly short and forked or absent; exothecial cell walls often collenchymatous; operculum long rostrate … Sematophyllaceae p.p.
12. Stems either dark red with leaves concave and ovate with alar cells subquadrate and thick-walled (often dark red), or stems wiry with leaves concave and ovate, weakly plicate, costa separated at base; alar cells enlarged and thin-walled … Hylocomiaceae p.p.
12. Plants lacking the combination of characters given above … 13.
13. Stems spreading to subascending, evenly foliate; leaves mostly crowded, ovate-short lanceolate to ovate (and concave); capsules long exserted; confined to montane or high elevations … Amblystegiaceae p.p.
13. Stems often pendent or lax and elongate; leaves often distant, often conspicuously so, except at branch and stem tips; leaves obovate to oblanceolate or elliptical, not concave or weakly so; capsules immersed; confined to lowlands … Hydropogonaceae p.p.
Section 9. Plants pleurocarpous. Leaves costate; costa single. Leaves strongly dimorphic, upper or lower leaves on stem smaller and differing in shape from larger lateral leaves.
1. Leaves on upper side of stem smaller; leaf margins lacking a border; costa of lateral leaves stoutly short excurrent … Racopilaceae
1. Leaves on lower side of stem smaller; leaf margins bordered or at least differentiated; costa of lateral leaves ending well below apex or weakly short excurrent … 2.
2. Plants procumbent; laminal cells unipapillose; apex of upper larger leaves obtuse-rounded to broadly acute; margins partially recurved; sporophytes immersed; semi-dry sites … Helicophyllaceae
2. Plants stipate-frondose; laminal cells smooth; apex of upper larger leaves rather sharply acute to short acuminate; margins plane; sporophytes exserted; moist montane sites … Hypopterygiaceae
[Sections 10-11. Plants pleurocarpous. Leaves monomorphic, usually differing only in that branch leaves are somewhat smaller, differing in shape or not, or that lateral leaves asymmetric and median leaves symmetric, or primary and secondary stem leaves differentiated; costa single.]
Section 10. Plants pleurocarpous. Leaves costate; costa single; laminal cells mammillose or papillose.
1. Laminal cells pluripapillose (cells with a single papillae mixed with some cells occasionally 2-3-papillose keyed out here also) … 2.
1. Laminal cells uniformly unipapillose or mammillose … 7.
2. Papillae rather numerous, over cell lumen and side walls … 3.
2. Papillae few, confined to cell lumen … 4.
3. Leaves smooth, not plicate, erect-appressed or wide-spreading; apices either acute to short acuminate or narrowly long acuminate … Meteoriaceae p.p.
3. Leaves plicate, loosely erect to spreading; apices broadly long acuminate … Trachypodaceae p.p.
4. Paraphyllia present on stems; leaves of stem and branch differentiated, the former ovate or triangular and acuminate, the latter ovate and acute or obtuse-rounded; stems regularly 1-3 pinnately branched; leaf apices ending in one or more papillae … Thuidiaceae p.p.
4. Paraphyllia absent; leaves of secondary stems and branches differing mostly in size; stems irregularly branched; leaf apices not papillose … 5.
5. Upper laminal cells isodiametric, mostly obscurely hexagonal … Anomodontaceae p.p.
5. Upper laminal cells elongate, linear to oblong-linear … 6.
6. Secondary stems rather rigidly erect, solitary or few branched; leaf margins strongly recurved … Pterobryaceae p.p.
6. Secondary stem soft or rigid, not erect, several to numerously branched; leaf margins not recurved, or if so only weakly so at base … Meteoriaceae p.p.
7. Stems differentiated between creeping primary stems and erect, subpendent or frondose / dendroid secondary stems … 8.
7. Stems not differentiated between primary and secondary stems, plants mostly forming mats or dense tufts … 13.
8. Creeping stems densely tomentose, leaves mostly obscurely hidden among tomentum; elongate branches (appearing as secondary stems) erect and often numerous; seta elongate, on terminal branches; calyptra mitrate-campanulate, often deeply lobed and plicate … Macromitriaceae
8. Creeping stems radiculose beneath, or naked; secondary stems erect to suberect, pendent or frondose to irregularly branched; seta lateral on stems … 9.
9. Upper laminal cells with papillae projecting at distal angles … 10.
9. Upper laminal cells with papillae over cell lumen … 11.
10. Plants not stipate, mostly irregularly branched; gemmae absent; seta very short, capsules immersed, sporophytes often several to rather numerous along one side of stems … Cryphaeaceae p.p.
10. Plants mostly stipate, often frondose; gemmae often present; seta elongate, capsules exserted … Pteryobryaceae p.p.
11. Leaf margins forming a border of somewhat elongate, smooth cells … Trachypodaceae p.p.
11. Leaf margins lacking a border, cells similar to intralaminal cells … 12.
12. Plants small, frondose; leaves ovate, smooth; upper laminal cells rhombic, walls entire … Neckeraceae p.p.
12. Plants medium sized to large, irregularly branched to subdendroid; leaves ovate-lanceolate, plicate; upper laminal cells rhomboidal to linear-rhomboidal, stellate … Prionodontaceae
13. Stem leaf margins strongly ciliate; laminal cell papillae strongly curved … Anomodontaceae p.p.
13. Stem leaf margins serrulate to serrate, not ciliate; laminal cell papillae erect or projecting … 14.
14. Plants forming tufts; leaves falcate-secund; some cells with papillae strongly projecting at distal angles on back of leaf … Hylocomiaceae p.p.
14. Plants forming mats; leaves not falcate-secund; papillae over cell lumen … 15.
15. Leaves loosely complanate, lateral leaves somewhat asymmetric, oblong acute-rounded; alar cells unequally distributed, more numerous on one side of costa … Stereophyllaceae p.p.
15. Leaves not complanate, ovate acuminate; alar cells equally distributed on either side of costa … Leskeaceae p. p.
Section 11. Plants pleurocarpous. Leaves costate; costa single; laminal cells smooth.
1. Laminal cells elongate, mostly 8 or more times longer than wide … 2.
1. Laminal cells isodiametric to short oval or rhomboidal, mostly 5 or less times longer than wide … 7.
2. Secondary stems erect, arising from densely tomentose short creeping primary stems; leaves oblong-lanceolate, to 5 mm long, ending in a long capillary tip, finely plicate; laminal cells linear and porose; epiphytic in high montane to zacatonal, páramo and puna … Lepyrodontaceae
2. Stems and branches creeping or subascending, not densely tomentose below; leaves variously shaped, mostly ovate- to oblong-lanceolate, apex acute to long acuminate, not ending in a capillary tip, if plicate then rather coarsely so; laminal cells weakly porose or not; various substrates and elevations … 3.
3. Plants pendent, dendroid or frondose, from a creeping primary stem (occasionally forming loose mats on banks or logs); stem and branch leaves often dimorphic or polymorphic in repeated series … 4.
3. Plants spreading or creeping, stems not differentiated between primary and secondary; stem and branch leaves differing only by degree of size and often by width … 5.
4. Plants mostly erect and frondose or dendroid, if pendent then leaves in 5-spiral rows; numerous filamentous pseudoparaphyllia present … Pteryobryaceae p.p.
4. Plants pendent or occasionally forming loose spreading mats; leaves not arranged in 5-spiral rows; filamentous pseudoparaphyllia absent … Meteoriaceae p.p.
5. Leaf alar cells asymmetrically distributed, more numerous on one side of costa … Stereophyllaceae p.p.
5. Leaf alar cells, if present, equally distributed on either side of costa … 6.
6. Plants mostly of wet habitats; leaves smooth; alar cells usually present, either thin-walled, enlarged and rounded or if quadrate to short rectangular then cells small and few; capsules horizontal, strongly asymmetric and curved … Amblystegiaceae p.p.
6. Plants of moist or semi-dry habitats, if aquatic then leaves broadly ovate, leaf margins serrulate throughout, upper laminal cells ca. 2:1; leaves plicate or smooth; alar cells quadrate to short rectangular, often rather numerous; capsules inclined to erect, weakly asymmetric … Brachytheciaceae p.p.
7. Stems differentiated between creeping primary stems and erect to suberect secondary stems … 8.
7. Stems creeping or spreading, occasionally subascending, not differentiated between primary and secondary stems … 15.
8. Secondary stems distinctly stipate, subdendroid to frondose; attenuate flagellate branches often present … 9.
8. Secondary stems not stipitate or weakly so, rigidly erect; tips short attenuate or not, flagellate branches absent, microphyllous branches present or not … 11.
9. Secondary stem and branch leaves loosely to strongly complanate, secondary stem leaves ovate to more commonly oblong or oblong-ligulate, apex mostly acute to acute-rounded, often coarsely toothed at apex … Neckeraceae p.p.
9. Secondary stem and branch leaves mostly teretely foliate; leaves ovate to ovate-short or -long acuminate … 10.
10. Secondary stem leaves abruptly long acuminate from a broad ovate base; margins serrulate to near base … Rigodiaceae
10. Secondary stem leaves gradually short acuminate; margins entire to serrulate at apex … Leptodontaceae p.p.
11. Leaves bordered with narrowly linear cells and conspicuously differentiated from inner laminal cells; calyptra mitrate or campanulate and fringed with ciliate hairs … Daltoniaceae p.p.
11. Leaves lacking a border, marginal cells not differing greatly from inner laminal cells; calyptra mitrate or cucullate, base lacking hairs … 12.
12. Secondary stem leaves loosely to strongly complanate … 13.
12. Secondary stem leaves terete foliate … 14.
13. Leaves broadly ligulate, apex truncate; costa ca. 3/4 leaf length; attenuate branches uncommon; gemmae absent … Neckeraceae p.p.
13. Leaves broadly elliptical, apex acute; costa percurrent; stem and branch tips short attenuate with gemmae in axil of reduced leaves … Adelotheciaceae
14. Microphyllous branches present; median laminal cells fusiform to fusiform-rhomboidal; leaf margins plane; seta elongate, capsules exserted … Leptodontaceae p.p.
14. Microphyllous branches absent; median laminal cells oval to oblong-oval; leaf margins recurved or plane; sporophytes several to many along one side of stem, seta very short, capsules immersed … Cryphaeaceae p.p.
15. Leaf costa ca. 1/2 leaf length or less; laminal cells thin-walled; plants rather delicate, stems readily breaking when removing leaves … 16.
15. Leaf costa mostly 2/3 leaf length or longer; laminal cells rather thick-walled; stems resilient … 17.
16. Leaf margins denticulate, ciliate or entire; peristome present or absent; plants common … Fabroniaceae p.p.
16. Leaf margins serrulate above alar region; peristome absent; plants rare … Myriniaceae p.p.
17. Upper laminal cells subquadrate; costa strongly flexuose distally … Anomodontaceae p.p.
17. Upper laminal cells rhombic to short rhomboidal or oval; costa straight or weakly flexuose … 18.
18. Branches ascending; leaf margins entire; costa often spurred below; exostome teeth ca. 1/2 the length of the endostome … Regmatodonaceae
18. Branches spreading or creeping; leaf margins dentate or serrulate; costa entire, not spurred; exostome subequal to or larger than endostome … 19.
19. Leaf apex relatively broad, acute; seta roughened or scabrous; capsule ovoid, to 1.1 mm long … Myriniaceae p.p.
19. Leaf apex relatively abruptly short to somewhat long acuminate; seta smooth; capsules cylindrical, mostly greater than 2 mm long … Leskeaceae p.p.