adapted from: An Enthusiasts Guide to the Liverworts and Hornworts of Ontario; Linda M Ley, Joan M Crowe; Lakeland University; 1999.
Genera in red are not known from the Northeast. Additional usage notes at bottom.
Plant thallose -- 1
Plant with distinct stem and leaves -- Leafy Liverworts 21
1A - Thalli thin, translucent, rosette-like. No distinct midrib. Nostoc colonies present, appearing as dark dots within thallus. Epidermal cells each containing only one chloroplast. Gemmae never present. Capsules with indeterminate growth, slender cylinders with no seta, opening with 2 valves ... Anthocerotales
1B - Thalli thick or thin. Usually with a thicker medial area or with differentiated tissue. Nostoc colonies absent (except for Blasia which has a midrib and produces gemmae). Epidermal cells with several small chloroplasts per cell. Capsules determinate, ovoid or cylindrical, usually borne on a seta, valves 4 or none -- 2
2A - Thallus thick and opaque, even at margins, with air spaces and, usually, distinct pores. Archegoniophores and/or antheridiophores sometimes present -- 3 (Marchantiales)
2B - Thallus thinner and often translucent towards margins, no air spaces or pores. No specialized archegonial or antheridial stalks present -- 12 (Metzgeriales)
3A - Plants very small, often forming tiny rosettes. Pores either not bordered or absent. Sporophytes embedded within thallus -- 4
3B - Plants small to large, with surface pores surrounded by at least two rows of cells. Sporophytes raised on stalked archegoniophores -- 6
4A - Usually aquatic and floating, occasionally stranded by receding water. Epidermis firm. Sterile -- 5
4B - Not floating. Epidermis frequently disintegrating. Often fertile ... Riccia
5A - Plants opaque. Forming incomplete, compact rosettes 5-9 mm. wide. Lobes with a distinct median groove. Pores distinct. Long, linear, violet ventral scales present in aquatic forms ... Ricciocarpus natans
5B - Plants light translucent green. Long-linear, freely though remotely dichotomous, 0.5-1 mm wide. Median groove, if present, only at apices. Pores inconspicuous. Scales lacking ... Riccia fluitans
6A - Air pores large, visible to the naked eye or under 5x magnification. Plants large and flat, thallus at least 6-10 mm. wide. Mesophytic. Surface reticulations clearly visible -- 7
6B - Air pores only visible under at least 10x magnification. Reticulations faint or none. Plants smaller, margins curled upwards or inrolled, thallus 6 mm or less wide. Xeromorphic to somewhat mesophytic -- 8
7A - Thallus large, leathery, 1-2 cm wide, up to 10+ cm long. Yellow-green, aromatic when bruised Pores simple and raised, centered within wide reticulations, often visible to the naked eye. Archegoniophores may be present. No gemmae ... Conocephalum salebrosum
7B - Thallus large, 7-15 mm wide, 4-6 cm long. Dark or dull green. Pores compound, with an inner cruciate opening. Circular gemmae cups on dorsal surface often present. Reticulations narrow, compressed to a dark strip at midline. Dioecious, often fertile, both archegoniophores and antheridiophores may be present ... Marchantia polymorpha
[Lunularia cruciata, a greenhouse weed, is similar but has crescent-shaped gemmae cups.]
8A - Plants medium, dull green, often with reddish purple crisped edges, hyaline tips of scales never visible at thallus margins -- 9
8B - Plants small, bright to greyish green with purple margins, hyaline scales often present at thallus margins -- 10
9A - Plants 6-10 mm wide, 2-3 cm long. Flat with crisped edges, never inrolled. Reticulations faint or invisible, surface appearing granular due to raised pores. Pores compound with an inner cruciate opening. Dioecious. Archegoniophores and antheridiophores produced ... Marchantia quadrata
9B - Plants 6-8 mm wide, 1-3.5 cm long. Dull, light green with narrow purplish margins inrolled when dry. Reticulations invisible. Pores simple, inconspicuous. Monoecious. Antheridia in thallus immediately behind archegoniophore ... Reboulia hemispherica
10A - Plants 3-5 mm wide, 8-15 mm long. Reticulations initially distinct, becoming faint with age. Pores sparse, simple, opening stellate. Thallus concave, grey to dull green, margins purple, fringed with hyaline to pale violet scales. Dioecious ... Clevea hyalina
10B - Pores circular. Thallus not fringed. Scales may project at apex -- 11
11A - Plants in rosettes, bright green with reddish to purplish margins, 1.5 mm wide, flat to slightly concave. Pores inconspicuous, circular. Apical tufts of scales absent. Monoecious. Antheridia within thallus, carpocephala on stalks lacking scales. Pseudoperianth present, conspicuous, segments hyaline to purplish. Tolerant, somewhat mesophytic, usually on damp soil ... Asterella tenella
11B - Plants fragrant, linear-lingulate, 2-3 mm wide, dark grey-green with raised purple margins. Pores raised. A conspicuous tuft of hyaline scales present at apices of female plants. Mostly monoecious. Antheridia within thallus, archegoniophores present, whitish scales present at base and apex. On exposed soil ... Mannia fragrans [M. sibirica; M. triandra]
12A - Thallus delicate, linear, flat, maximum 1 mm wide. Branching various, frequent -- 13
12B - Thallus more robust, often crisped or undulate, 2 mm or more wide. Dichotomously, often sparsely branched -- 17
13A - Thallus with a distinct midrib. Dichotomously branched. Marginal hairs present. Autoecious, gametangia on short branches from postical side of midrib -- 14
13B - Thallus with no distinct midrib. Appearing pinnately or subpalmately branched. Gametangia on short lateral branches -- 15
14A - Marginal hairs in pairs. Gemmae absent ... Metzgeria conjugata
14B - Marginal hairs single. Multicellular marginal gemmae often present ... Metzgeria furcata; M. crassipilis
15A - Pale translucent green, usually prostrate, 0.3-1 mm wide. Branches regularly 2-3 pinnate, with a conspicuous hyaline border on younger branches. Gemmae rare. Autoecious. On wet rocks or in marl bogs and fens ... Riccardia multifida
15B - Opaque, branches ascending when crowded, irregularly 1-2-pinnate or subpalmate. No clear border. On less wet substrates -- 16
16A - Bright or deep green throughout, 0.5-1 mm wide. Often closely adherent to substrate, branches erect with crowding. Gemmae rare. Autoecious. On logs and peat ... Riccardia latifrons
16B - Deep, pure green, older parts brown, 0.15-0.3 mm wide. Branches crowded and stiffly erect. Gemmae frequent, 2-celled, elliptical. Dioecious. Only on logs ... Riccardia palmata
17A - Light yellowish green, 1.5-2.5 mm wide, freely dichotomously branched, forming rosettes with wavy edges and a border of black dots (Nostoc colonies). Stellate gemmae and/or gemmae flasks often present. Dioecious ... Blasia pusilla
17B - Thalli various, sparingly branched, not in rosettes, never with black dots embedded in thallus, gemmae absent -- 18
18A - Midrib not differentiated. Thallus flat, thick, pure to yellow-green, appearing "greasy", 4-6 mm wide. Dioecious, but antheridial and/or archegonial branches frequently present, short and lateral ... Aneura pinguis; A. sharpii
18B - Midrib variously differentiated. Thallus undulate to crisped, never "greasy", antheridia and archegonia always dorsal -- 19
19A - Plants robust, 8-12 mm wide, light to deep green, sometimes reddish, somewhat opaque, flat to crisped. Midrib thick and broad, diffusing gradually into lamina, which gradually thins to a translucent margin. Monoecious. Antheridia sunken into dorsal surface of midrib, appearing as bumps ... Pellia epiphylla; P. neesiana; Apopellia megaspora
19B - Plants green and translucent. Midrib narrower and rather abruptly differentiated. Dioecious. Antheridia dorsal on midrib, subtended by scales, and archegonia dorsal on leading thalli, surrounded by scales -- 20
20A - Midrib with an opaque central strand. Thallus green, long-linear, 2-6 mm wide, simple, thin, flat to somewhat undulate, translucent. Can have a "fishy" smell ... Pallavicinia lyellii
20B - Midrib lacking a visible opaque strand. Thallus light, translucent green, pleasantly aromatic, undulate or crispate and sometimes freely branched, 4-7 mm wide ... Moerckia flotoviana
21A - Stem with lateral leaf-like lamellae, irregularly notched and lobed. Rhizoids violet. Antheridia and archegonia dorsal on midrib, subtended by scales. Pseudoperianth campanulate. Frequently fertile. A pioneer on inorganic soil ... Fossombronia
21B - Stem clearly defined, with thin "leaves" in 2 rows, with or without a third row (usually smaller) on the ventral side of the stem. Sporangia terminal on leading stems or branches. Substrates various -- 22
Note: Measurements for the following refer to a single shoot.
22A - Leaves deeply divided into thin filaments, 1 or 2 cells wide, OR divided into lobes which are fringed with long cilia -- 23
22B - Leaves various, entire, toothed, lobed or complicate-bilobed, occasionally with basal cilia -- 27
23A - Leaves deeply divided to the base into 3 or 4 thin filaments, plants very small -- 24
23B - Leaves divided into two or more lobes fringed with cilia, plants small to large -- 25
24A - Dull, light to dark green, 0.2-0.4 mm wide. Leaves deeply divided into 3-4 filaments, 2 cells wide at base. Underleaves similar, smaller than leaves. In bogs ... Kurzia pauciflora, sylvatica
24B - Pellucid, light to yellow-green, 0.7-0.9 mm wide. Leaves divided into 3-4 filaments, 1 cell wide throughout. Underleaves similar in size to leaves. On soil, logs or rocks ... Blepharostoma trichophyllum
25A - Yellowish-green, whitish when dry. Robust, shoots including branches 1.5-3 cm wide. 2-3 pinnately branched, plumose. Leaves fringed with filaments, 4-5-lobed nearly to base, with secondary lobes. Underleaves similar but half size ... Trichocolea tomentella
25B - Plants smaller, never whitish. Leaves divided into 3-5 lobes (unequally bilobed, subdivided) Underleaves shallowly bilobed and fringed -- 26
26A - Green to gold to (occasionally) reddish or purplish brown, 0.8-1.5 mm wide. Dorsal lobe 6-10 cells wide at base Creeping over substrate. Freely fertile. On rotting logs or tree trunks ... Ptilidium pulcherrimum
26B - Green to reddish brown or coppery, 1.6-3 mm wide. Dorsal lobe 15-22 cells wide at base. More erect growth form. Rarely fertile. Usually on exposed rocks ... Ptilidium ciliare
27A - Leaves obliquely inserted and incubous -- 28
27B - Leaves obliquely inserted and succubous OR transversely inserted -- 49
28A - Leaves 3-4-lobed, lobes finger-like, strongly deflexed. Underleaves similar, 2/3 size of leaves. Plants small, 0.5-0.7 mm wide, regularly pinnately branched ... Lepidozia reptans
28B - Leaves either entire or dentate at apices, OR complicate-bilobed, with the differentiated ventral lobe folded under and hidden by the dorsal lobe -- 29
29A - Leaves entire or dentate Underleaves present, ovate, wider than long -- 30
29B - Leaves complicate-bilobed. Underleaves ovate, mostly longer than wide, OR lacking -- 37
30B - Plants opaque. Leaves ovate-lanceolate, somewhat asymmetric, narrowed to a 2-3-dentate apex. Ventral stolons frequently present. gemmae lacking -- 31
30B - Plants pellucid. Leaves broadly ovate, entire or sometimes bidentate at apex. Gemmae often present, usually on attenuate shoots -- 33
31A - Plants green, small and delicate, 1.5-2 mm wide, 1-2.5 cm long. Leaf apices with two small teeth or a single point, not deflexed. Underleaves rounded, oval, very shallowly 3-4-lobed. Sections of stem with deciduous leaves usually present. Rare, on cliffs and rock faces ... Bazzania denudata
31B - Plants large to robust. Leaf apices tridentate, strongly deflexed -- 32
32A - Plants deep green to reddish brown, large, 1.5-2 mm wide, 3-5 cm long. Underleaves oval, shallowly 3-4-lobed. Rare, amongst other bryophytes on cliffs ... Bazzania tricrenata
32B - Plants green to olive-green, robust, 3-6 mm wide, 3-5 cm long. Underleaves oval, irregularly and shallowly 4-5-lobed, margins sharply dentate. Common, forming conspicuous cushions over forest floor ... Bazzania trilobata
33A - Small, less than 2 mm wide and ± 1 cm long. Underleaves bilobed, deeply cleft. Cells with small bulging trigones. On organic substrates -- 34
33B - Larger, 2-4 mm wide and 2-5 cm long. Underleaves entire, notched or bilobed. Cells without bulging trigones. Substrates various -- 35
34A - Pale to yellow-green. Underleaves large, at least twice width of stem, often with lateral lobes. Gemmae infrequent. Found on decaying logs ... Calypogeia suecica
34B - Whitish green, transparent. Underleaves little wider than stem, if toothed then only on one side. Gemmae common. On or amongst Sphagnum ... Calypogeia sphagnicola
35A - Underleaves distinctly bilobed. Leaves narrowly ovate to wider than long, marginal cells undifferentiated -- 36
35B - Underleaves suborbicular to shallowly bilobed, 2-3x wider than stem. Leaves clearly longer than wide, widest at base, tapering to a rounded tip. Marginal cells mostly isodiametric, but with short interrupted rows of elongate cells. Pale to greyish green, 2.5-3 mm wide. Gemmae frequent. Common and tolerant ... Calypogeia integristipula
[Calypogeia neesiana is very similar, but has leaves widest above the base, more truncate apices and a complete border of elongate cells.]
36A - Yellow-green to whitish green, 1.8-3.5 mm wide, 2-5 cm long. Leaves as wide or wider than long, apices rounded, blunt, rarely bidentate. Underleaves bilobed 1/4-1/2, twice width of stem. Tolerant, preferring constantly moist, shady sites ... Calypogeia muelleriana
36B - Whitish green, 2.2-2.9 mm wide. Leaves narrowly ovate to as wide as long, blunt to acute, occasionally bidentate. Underleaves distant, deeply bilobed, barely wider than stem, with a short, blunt angulation on one or both sides. On mineral soils, rare ... Calypogeia neogaea
37A - No underleaves present -- 38
37B - Underleaves distinct -- 39
38A - Plants very small, 0.5-0.7 mm wide, 3-9 mm long. Pellucid, yellowish green. Dorsal lobes pointed. Cells papillose. Ventral lobule inflated along posterior margin of dorsal lobe. Gemmae lacking. Perianths cylindrical, 5-angled, abruptly narrowed to a beaked mouth ... Cololejeunea biddlecomiae
38B - Plants larger, 1.4-2 mm wide, 1-2 cm long Opaque, bright yellow-green. Dorsal lobes round. Cells smooth. Lobule not inflated, subquadrate. Discoid marginal gemmae usually present. Perianths compressed, wide-mouthed ... Radula complanata
39A - Plants large, up to 4 mm wide and 10 cm long. Dorsal lobes broadly ovate. Lobules not inflated, parallel to long axis of stem, keeled. Underleaves entire. Perianths infrequent, flattened above, wide-mouthed -- 40
39B - Plants medium to very small, less than 1.5 mm wide and 4 cm long. Lobules inflated, not necessarily parallel to stem, either keeled or stalked. Underleaves bilobed. Perianths frequently produced, cylindrical, narrowed to a beaked mouth -- 42
40A - Dull to blackish green, bipinnate, aquatic. 2-4 mm wide, 4-10 cm long. Lobules flat, small, Ungulate. Keel vestigial. Underleaves narrow, flat, short-decurrent. On wet substrates ... Porella pinnata
40B - Yellowish green or olive-green, never aquatic. Keel short and strongly arched. Underleaves wider than stem, with reflexed margins, long-decurrent. On bark or rock, dry or moist ... Porella platyphylla
42A - Ventral lobe keeled, somewhat inflated, lying at an angle to the stem, parallel to the posterior leaf margin. Small, 0.9-1.2 mm wide Clear, pale green, dried material "sparkling" under microscope. Perianths 5-angled ... Lejeunea cavifolia
42B - Ventral lobe stalked, parallel to stem, usually very inflated and "helmet"-shaped. Perianth 3-angled, sometimes with supplementary ridges -- 43
43A - Dorsal lobes with ocelli, i.e., oblique lines of colored cells in leaf -- 44
43B - Dorsal lobes lacking ocelli -- 45
44A - Medium, 0.8-1.3 mm wide, 3-4 cm long. Dark reddish brown, glossy. Dorsal lobes tightly overlapping Underleaves as wide or wider than long. Lobules somewhat distant from stem, with apices pointing away from it. Mostly on rock ... Frullania asagrayana
44B - Very small, 0.6-0.9 mm wide. Orange-brown, slightly glossy. Dorsal lobes more relaxed. Underleaves longer than wide. Lobules close to stem, apices leaning towards it. Mostly on bark of cedar trees ... Frullania selwyniana
45A - Erect worm-like branches bearing only underleaves and bases of deciduous leaves usually present. Deep green to reddish brown, 0.5-0.9 mm wide. Lobule large, 1/2-3/4 dorsal in size ... Frullania bolanderi
45B - Worm-like branches lacking -- 46
46A - Dorsal lobes truncate at base. Autoecious. Lobules as wide as long, inflated or not -- 47
46B - Dorsal lobes auriculate at base. Dioecious. Lobules longer than wide, inflated (except sometimes near gynoecia) -- 48
47A - Lobules inflated, very large - subequal in size to dorsal lobes, close to stems Plants reddish brown, very small, 8-10 mm long, 0.6-0.7 mm wide ... Frullania oakesiana
47B - Many lobules not inflated, less than half the size of the dorsal lobes, spaced away from stems. Green to brownish. Small, up to 1 mm wide ... Frullania inflata
48A - Lobules evenly inflated, less than half size of dorsal lobes. Underleaves longer than wide, bilobed, not toothed. Dull, deep green to brown to blackish, 0.5-0.8 mm wide, wiry. Perianths frequently present, smooth ... Frullania eboracensis
48B - Lobules inflated but pinched at opening, less than half size of dorsal lobe. Underleaves wider than long, bilobed and toothed. Dull green to reddish brown, 0.9-1.4 mm wide. Perianths with supplementary keels, tuberculate, infrequent ... Frullania brittoniae
49A - Leaves mostly entire, rounded or oval, succubous. May be emarginate or denticulate -- 50
49B - Leaves 2-4-lobed or complicate-bilobed with dorsal lobe folded over ventral, similar to it, but smaller. Succubous or transverse -- 65
50A - Underleaves absent (sometimes vestigial on fertile shoots) -- 51
[Note: The underleaves of Plagiochila porelloides are often difficult to find. This large polymorphic species may key out under 50A, but is distinguished by its ovate-rotund leaves with widely and strongly deflexed dorsal margins. See couplet 60.]
50B - Underleaves present, sometimes hidden by rhizoids -- 57
51A - Prostrate, 1.7-2.4 mm wide, dark green. Leaves often red-tinged, rounded to squarish, upper occasionally notched, overlapping, wide-spreading. Perianths frequent, fringed at mouth, not contracted. Vestigial underleaves sometimes present. Ubiquitous, mostly on logs ... Syzygiella autumnalis
51B - Yellowish green to brownish (if reddish, then only on rhizoids, bases of leaves and stems.) Leaves round to ovate-oblong. Perianths infrequent contracted to mouth, not fringed. Underleaves totally lacking -- 52
52A - Rhizoids and leaf bases reddish purple. Leaves wider than long -- 53
52B - Rhizoids colorless to brownish. No reddish-purple coloring -- 54
53A - Yellowish to pure green, 1.5-2.2 mm wide. Leaves not bordered, kidney-shaped to orbicular, wide-spreading below to erect-spreading above, undulate, long-decurrent. Leaf bases and underside of stem carmine ... Solenostoma hyalinum
53B - Pellucid, pale to yellowish green, reddish in sun, 1.4-2 mm wide. Leaves with a slightly elevated border of quadrate-rectangular cells, erect-spreading, round, concave. Leaf bases reddish purple ... Solenostoma crenuliforme
54A - Leaves elliptical to rectangular, longer than wide, wide-spreading -- 55
54B - Leaves cordate or roundish, as wide or wider than long, erect-spreading to erect-appressed -- 56
55A - Clear green to brownish, medium-sized, 2-2.5 mm wide. Leaves ovate-rectangular, sometimes notched, apices somewhat deflexed. Perianths rare, cylindrical, mouth narrowed abruptly to a central beak. On acidic substrates, mesophytic ... Liochlaena lanceolata
55B - Dull green to blackish, small, 1-2 mm wide. Leaves narrowly ovate to broadly elliptical, entire, base somewhat concave. Perianths frequent, cylindrical, narrowed to a pleated mouth. On damp rocks and cliffs ... Jungermannia pumila
56A - Dull green to blackish purple. Plants large, 2-3.5 mm wide. Leaves cordate, embracing stem, not bordered. Rare, aquatic ... Jungermannia exsertifolia ssp. cordifolia
56B - Whitish or yellowish green to green, often reddish in sun. Plants small, 0.9-1.3 mm wide. Leaves circular, concave, bordered with swollen thick-walled cells. On inorganic soils ... Solenostoma gracillimum
57A - Rhizoids restricted to bases of underleaves, leaving them clearly visible -- 59
57B - Rhizoids evenly distributed over stem surface. Underleaves either very small and inconspicuous, or larger and hidden by a mat of rhizoids -- 60
59A - Whitish or yellowish green, transparent, 1.8-3.2 mm wide Leaves oblong to rounded-truncate, sometimes notched, convex, longer than wide, slightly decurrent. Underleaves nearly as wide as stem ... Chiloscyphus pallescens
[An aquatic phase of C. pallescens var. fragilis, is a deep to blackish green and large, 3.5-5 mm wide, with very large cells.]
59B - Dull green to yellow-green, rather opaque, 2 4-3.5 mm wide. Leaves rounded, quadrate, noticeably decurrent, as wide as long, undulate. Underleaves smaller, not as wide as stem ... Chiloscyphus polyanthos
[An aquatic phase of C. polyanthos var. rivularis, is a deep to blackish green, 2-3 mm wide, with very small cells.]
60A - Underleaves minute. Plants olive to deep green, polymorphic, large, 1.8-6 mm wide, up to 10 cm long. Leaves ovate to subrotund, often denticulate, strongly decurrent, dorsal leaf margins strongly and widely deflexed from base to apex. Trigones small, rarely bulging. Rhizoids infrequent and scattered ... Plagiochila porelloides
60B - Underleaves larger, lanceolate. Dorsal leaf margins erect or incurved. Trigones bulging -- 61
61A - Leaves orbicular, rigid and concave Plants small to medium, 2 mm wide or less, sometimes with thread-like postical branches (stolons). Leaf cells ± 25µm Underleaves small, indistinct. Rhizoids scattered -- 62
61B - Lower leaves spreading, upper erect. Plants robust, ca. 3 mm wide, lacking postical stolons. Underleaves large, distinct but hidden in a thick rhizoid mat. Leaf cells 40-70µm -- 63
62A - Pale green to whitish green, 0.8-1.1 mm wide. Leaves subrotund, strongly concave, slightly emarginate, closely imbricate, plants appearing terete. Leaf cells with confluent trigones ... Odontoschisma macounii
62B - Yellowish or brownish green to reddish or blackish, 1-1.6 mm wide, not terete. Leaves ovate-subrotund, moderately concave. Trigones rarely confluent -- 64
63A - Pure green to yellow or reddish brown. Lower leaves erect-spreading, ovate. Upper leaves erect, ovate-lanceolate, frequently bearing gemmae. On peat ... Mylia anomala
63B - Carmine-red to purplish brown. Leaves broad-ovate to orbicular, lower spreading, upper erect, gemmae infrequent, in bundles on leaf margins. On acid rocks ... Mylia taylorii
64A - Yellow-green in shade, reddish brown to purplish black in sun. Leaves concave, closely overlapping, erect to erect-spreading, slightly decurrent. Underleaves small, lingulate, ± bidentate. On logs ... Odontoschisma denudatum
64B - Green to brownish or blackish brown. Leaves more distant, spreading to patent, not decurrent. Underleaves larger, triangular. On peat ... Odontoschisma elongatum
65A - Leaves mainly with 3 to 4 lobes. (If only two small, sharp lobes as in the small Tritomaria spp., then leaves markedly asymmetric and concave.) -- 66
65B - Leaves bilobed OR complicate-bilobed -- 77
66A - Leaves transversely inserted -- 67
66B - Leaves succubous -- 71
67A - Plants medium, terete, up to 5 cm long. Leaves deeply divided into 4(3) lobes. Lobes erect from a spreading leaf base. Underleaves present -- 68
67B - Plants small to medium, not terete. Leaves less deeply divided, (2)3-lobed, asymmetric. No underleaves -- 69
68A - Filiform. Shiny olive-green to yellow-brown. Leaf lobes channeled. Leaf and lobe margins dentate. Underleaves large, similar shape to leaves, deeply bilobed. Forming dense, pure mats ... Tetralophozia setiformis
68B - Rigid. Olive-green to brownish to blackish. Leaf lobes with reflexed margins, leaf bases ciliate. Underleaves small, divided to base into two lanceolate lobes, with ciliate margins. Forming tufts or mixed with other bryophytes ... Barbilophozia quadriloba
69A - Leaves only slightly asymmetric, almost equally trilobed sub rectangular, erect-spreading, concave, lobes acute. Plants small, 1.5-1.8 mm wide, green to brownish. Gemmae frequent on upper leaves, reddish brown ... Tritomaria scitula
69B - Leaves definitely asymmetric. Dorsal lobe about 1/2 size of ventral, often infolded -- 70
70A - Plants 1.2-1.8 mm wide Leaf cells very small. Gemmae 2-celled, elliptical ... Tritomaria exsecta
70B - Plants 1.6-2 mm wide. Leaf cells larger. Gemmae 2-celled, polyhedral ... Tritomaria exsectiformis
71A - Plants large, ± 3 cm long, ± 2 mm wide. Leaves mostly 4(3)-lobed, very obliquely inserted, or appearing so -- 72
71B - Plants medium to small. Leaves 2-, 3- or 4-lobed, obliquely inserted -- 74
72A - Green to yellowish brown. Leaves asymmetric, rounded, wider than long, fluted and widely spreading, distinctly trilobed. Anterior insertion of leaf is transverse. No underleaves. Gemmae rare, yellowish brown ... Tritomaria quinquedentata
72B - Leaves rectangular, more or less symmetrical, 4-lobed. Underleaves present or inconspicuous to none -- 73
73A - Green to brown. Leaves unequally lobed for 1/3 of length, at least some lobes sharply pointed, ciliate at base. Underleaves large, bilobed, ciliate. Reddish gemmae common ... Barbilophozia hatcheri
[Barbilophozia lycopodioides would key out here. This is a robust, montane species, with leaf lobes more markedly apiculate than B. hatcheri]
73B - Dark green to yellowish brown. Leaves not ciliate at base, lobed ± 1/4 of length, lobes blunt, subequal. Underleaves usually none or inconspicuous. Gemmae usually absent ... Barbilophozia barbata
74A - Plants often bearing several attenuate gemmiferous shoots with appressed leaves. Pure green, occasionally brownish, medium-sized, 0.8-1.4 mm wide. Leaves sub equally 3-lobed, incurved from a spreading base. Pale greenish gemmae, quadrate to stellate. Underleaves occasional, vestigial ... Neoorthocaulis attenuatus
[N. binsteadii, an arctic-alpine bog species, would key out here]
74B - Attenuate shoots lacking. Plants small, leaves 2-4-lobed. No underleaves -- 75
75A - Opaque, bluish green, 1.3-1.6 mm wide, 4-10 mm long, somewhat fleshy Upper leaves 3-4-lobed, apiculate, crowded, crispate. Leaf cells ± 30g. Gemmae pale green, 1-2-celled, polyhedral. On decaying logs and peaty soil ... Lophozia incisa
75B - Translucent, whitish, pale or pure green with some purplish or reddish pigmentation. Leaf cells very large, ± 40µm. Gemmae 1-celled -- 76
76A - Whitish to pale green, leaf tips often reddish but underside of stem green, 1-2.5 mm wide, 1-3 cm long, cespitose. Leaves polymorphic, delicate, crispate, 2-4-lobed, subquadrate to wider than long. Gemmae copious, oval, green to reddish tinged. Damp, sandy areas ... Lophozia capitata
76B - Pellucid, pure green, underside violet, delicate, creeping and scattered, 1.8-2 mm wide. Leaves subquadrate to wider than long, flaccid, distant and spreading, 2-4-lobed. Gemmae green, spherical to oval. Peat bogs ... Schistochilopsis incisa
[S. grandiretis, an arctic-alpine species, would key out here.]
77A - Plants with complicate-bilobed leaves -- 78
77B - Plants with bilobed leaves -- 88
78A - Both lobes narrow and elongate, distinctly pointing in different directions. Ventral lobes ca. 2-3x length of dorsal. Margins dentate. Cuticle papillose. Gemmae common, green, polygonal to stellate ... Diplophyllum
78B - Lobes various, rounded to short-lingulate, ventral lobes ± 2x dorsal. Cuticle not papillose. Gemmae smooth, oval to elliptical, color varies -- 79
79A - Very small species, less than 10 mm long. Gemmiparous shoots with reduced leaves abundant, erect and crowded. Gemmae oval to elliptical. On decaying logs -- 80
79B - Larger species, up to 10 cm long. Gemmae elliptical, on margins of less modified leaves on normal shoots. Habitats vary -- 81
80A - Plants green, lower parts brownish, upper whitish, 1-1.5 mm wide. Ventral lobe ovate-triangular, dorsal lobe half size of ventral. Leaves bordered with thick-walled cells; inner cells thin-walled. Gemmae rust-red, 2-celled. on apices of reduced equally bilobed leaves ... Scapania glaucocephala
80B - Plants green to yellowish green to brownish, 0.6-1.2 mm wide. Ventral lobe narrowly obovate, dorsal lobe 3/4 size of ventral. Leaves lacking a border. Gemmae bright red, 1 -celled, on leaves, lower bilobed, upper orbicular ... Scapania apiculata
81A - Whitish green Leaves ventrally long-decurrent, gemmae 2-celled -- 82
81B - Plants never whitish green Leaves decurrent or not. Gemmae 1- or 2-celled, elliptical -- 83
82A - 1 -2.5 mm wide, 6-12 mm long Leaf lobes obovate, rounded, entire nearly equal in size, dorsal spreading out from ventral lobe. Gemmae at apices of triangular upper leaves, brownish, elliptical. On rock. Arctic-alpine ... Scapania cuspiduligera
82B - 1.5-2.5 mm wide, 1-2 cm long. Leaves with dorsal and ventral lobes ovate, pointed, dentate. Dorsal half size of ventral. Gemmae reddish, elliptical, gemmiferous leaves becoming reduced. On logs or rock. Subarctic ... Scapania umbrosa
83A - Plants small, ± 2 mm wide, 6-15 mm long. Ventral lobes narrow, ovate, ovate-lanceolate or lingulate, nondecurrent. Gemmae 2-celled -- 84
83B - Plants medium to large, 2-5 mm wide, 1.5 to 10+ cm long. Ventral lobes obovate, cordate or rotund, decurrent or not. Gemmae 1- or 2-celled -- 85
84A - Plants deep to blackish green. Dorsal lobe less than 1/3 size of ventral. Large, persistent oil-bodies filling cell cavity (1 or 2 only in central leaf cells). Gemmae brown to reddish brown ... Scapania gymnostophila
84B - Plants green to yellow-brown. Ventral and dorsal lobes oblong-ovate with a sharp point. Dorsal lobe 1/2 size of ventral, keel less than half length of ventral lobe. Oil bodies not persistent, 2-6 per cell. Gemmae green ... Scapania mucronata
[Scapania curta; S. lingulata; S. scandica would also key here.]
85A - Green to reddish pink, stem ± blackish brown. Leaves with margins spinose-ciliate. Ventral lobes obovate, long-decurrent, often deflexed, dorsal lobes reniform, decurrent. Keel weakly arched, 1/4-1/3 length of ventral lobe Gemmae brownish to reddish, 1-celled ... Scapania nemorea
85B - Leaves with margins entire, denticulate or with scattered teeth. Ventral lobes not deflexed. Gemmae 2-celled -- 86
86A - Yellowish green to yellowish brown. Ventral lobes cordate to rotund, apiculate. Dorsal lobe similar, pointed, 1/2 ventral in size. Margins slightly denticulate. Keel very short and strongly arched. Leaves not decurrent, but with very arched insertions. Gemmae reddish to reddish brown ... Scapania paludicola
[Scapania spitzbergensis is somewhat similar with margins spinose-dentate and gemmae greenish to pinkish]
86B - Ventral lobe ovate to obovate, dorsal lobe sub rectangular. Keel straight to weakly arched. Gemmae greenish to red -- 87
87A - Green to violet-red, stems purplish black. Ventral lobe decurrent, obovate. Margins entire to denticulate with a border of thick-walled cells. Keel straight, 1/4-1/2 length of ventral lobe. Gemmae greenish to red, oval ... Scapania undulata
[Scapania subalpina is a similar but on rocks in streams in subalpine/alpine sites]
87B - Yellowish green to brownish. Ventral lobe not markedly decurrent, rotund-ovate, apiculate. Dorsal lobe 1/2-2/3 ventral Margins with scattered 1-celled teeth at leaf apices, not bordered. Keel weakly arched, 1/3-1/2 length of ventral lobe. Gemmae pale green, long-elliptical ... Scapania irrigua
[Scapania hyperborea is similar but golden to reddish brown, gemmae mostly 2-celled and oval, occasionally 1-celled, pinkish to red]
88A - Plants very small, less than 0.5 mm wide and 5 mm long. Stems opaque. Leaves transverse. Lobes divergent. Gemmae 2-celled, oval or elliptical -- 89
88B - Plants small to large OR, if very small, with translucent stems having a central strand. Leaves mostly succubous, sometimes transverse. Lobes not divergent, often connivent -- 94
89A - Leaves cleft to within 2 or 3 cells of the base, usually toothed at least at base, distantly spaced. Lobes lanceolate. Gemmae greenish. Growing over Sphagnum -- 90
89B - Leaf lobes less deeply cleft, occasionally toothed at base, touching to closely overlapping. Lobes triangular. Not in bogs -- 91
90A - Pale yellow-green to bluish purple. Leaves remote, with a few sharp teeth. Underleaves either linear (2 cells wide at base) or bifid (lobes 2 cells wide at base). Gemmae occasional on erect shoots ... Cephaloziella elachista
90B - Pale green to copper-red. Leaves not so distant, entire or dentate with spinose teeth at base. Underleaves finger shaped or bilobed. Gemmae rare ... Cephaloziella spinigera
91A - Reddish brown to purplish brown to black Leaves bilobed 1/2 their length with erect-spreading, upcurved lobes, occasionally dentate. Underleaves variable, lanceolate and 2-3 cells wide to bifid and 5-7 cells wide. Gemmae yellow-green to purplish. In mats on insolated rock outcrops or ledges ... Cephaloziella divaricata
91B - Green to brownish green. Lobes straight. On soil, rotting logs or shaded rock -- 92
92A - Plants green to brownish. Leaves square to trapezoidal, spreading to squarrose, 1/2-3/4-bilobed. Lobes acute, 6-9 cells wide at base. No underleaves on sterile shoots. Gemmae at leaf margins, greenish or brownish. On shaded rock outcrops, soil or rotting logs ... Cephaloziella hampeana
92B - Plants green or brownish, with reddish pigmentation. Leaves erect-spreading, 1/2-bilobed. Leaf lobes lanceolate, 4-6 cells wide at base. Underleaves sometimes present -- 93
93A - Plants small, reddish to reddish brown. Leaves ovate, cells thick-walled. No underleaves Perianths frequently present. Weedy, on acid substrates ... Cephaloziella rubella
93B - Minute, green to brownish. Leaves as broad as long, pellucid. Underleaves sporadic, minute. Often highly gemmiferous, leaving leaf edges lacerate, gemmae pale green to reddish brown. On rotting logs ... Cephaloziella rubella var. sullivantii
94A - Plants small to minute, stems translucent with a central strand. Leaf lobes lanceolate, acute. Underleaves lacking. Sinus acute to circular -- 95
94B - Plants small to robust, with opaque stems. Lobes various, sinus shallow, lunate to acute. Underleaves absent or present -- 100
95A - Leaf lobes connivent. Leaves rotund to circular, horizontally spreading, decurrent. Cells thin-walled -- 96
95B - Leaf lobes not connivent. Leaves erect to wide-spreading, not decurrent. Cells thick-walled -- 98
96A - Pellucid, yellowish to whitish green, 0.9-1 mm wide. Leaves 8-12 cells broad, long-decurrent Lobes slightly asymmetric, 3-5 cells wide, strongly connivent. Leaf cells very large, pellucid. Gemmae rare. Acid habitats ... Fuscocephaloziopsis connivens
96B - Pure green or yellowish green Leaves obliquely inserted, lobes slightly to distinctly connivent, gemmae more frequent -- 97
97A - Relatively robust, 1 -1.2 mm wide. Pure green, very occasionally reddish-tinged. Leaves 20-28 cells wide. Lobes 8 -12 cells at base, ventral somewhat wider. Lobes slightly connivent, leaf cells large, leaves slightly decurrent. Gemmae greenish, 1 -celled, elliptical, forming a "head" at tip of shoot. Calcium tolerant ... Fuscocephaloziopsis pleniceps
97B - Small, 0.4-0.6 mm wide, pale yellowish green. Leaves 8-10 cells wide. Lobes 3(4) cells wide, distinctly connivent. Leaf cells smaller, leaves distinctly decurrent. Gemmae green, 1-celled, angular, frequent at shoot apices, not forming "heads". With a wide ecological amplitude, most common on logs ... Fuscocephaloziopsis lunulifolia
98A - Dull green to brownish, 0.4-0.6 mm wide. Leaves ovate, as broad as long, 11-18 cells wide. Lobes triangular, 4-8 cells wide, occasionally somewhat connivent Cells very small. Gemmae frequent, on attenuate shoots. On logs ... Fuscocephaloziopsis catenulata
98B - Pale or whitish green to golden or reddish brown. Leaves longer than wide, bilobed 1/2-1/3 their length. Lobes lanceolate, parallel, never connivent. Substrates various -- 99
99A - Minute, 0.15-0.3 mm wide, green to yellowish green. Leaves almost transverse, ovate to rectangular, 7-8 cells wide at base. Lobes 2-3 cells wide at base, spreading. Cells small No gemmae. On rotting logs ... Cephalozia macounii
99B - Pellucid, pale green to whitish, golden or reddish brown in sun, 0.6-1 mm wide. Leaves sub transverse, ovate, slightly concave, 12-16 cells wide. Sinus 1/2 leaf length. Cells large. Gemmae rare, whitish green. On wet, exposed rocks, mineral soils or peat ... Cephalozia bicuspidata
100A - Leaves distinctly transverse -- 101
100B - Leaves mostly succubous, occasionally almost transverse -- 110
101A - Underleaves present, large, lanceolate to bilobed. Plants medium, 0 6-1 2 mm wide, 2-5 cm long, golden brown. Leaves subrotund, wider than long occasionally 3-lobed, imbricate, lobes blunt and incurved from a spreading base ... Schljakovia kunzeana
101B - Underleaves absent. Plants small to medium. Lobes various, incurved or spreading -- 102
102A - Plants small, 0.5-0.8 mm wide, 8-20 mm long, green to reddish. Leaves extremely concave, almost saccate. Lobe points very long and thin, usually curved inward. On decaying logs ... Nowellia curvifolia
102B - Leaves concave to channeled, never saccate. Leaves rigidly inserted, lobes acute to blunt, never filamentous -- 103
103A - Leaves erect to spreading, concave to channeled, unequally bilobed, dorsal lobe smaller. Lobes acute to blunt, incurved or straight. Reddish angular gemmae frequently present -- 104
103B - Leaves concave, equally lobed. Lobes blunt to acute, spreading from a sheathing base. Gemmae never present. On wet rocks -- 108
104A - Plants large. Leaves slightly to strongly concave, dorsal bases arched over and extending beyond stem, closely overlapping. One or both lobes incurved. Gemmae rare. Usually on vertical rock faces -- 105
104B - Plants small to medium. Leaves channeled, longer than wide, more widely spaced, bases not arched over stem. Lobes not incurved. Gemmae frequent, on reduced-leaved attenuate shoots -- 106
105A - Olive-green, brown or yellow-brown. Large, 1.2-2.5 mm wide, 2-5 cm long. Leaves very asymmetric, cupped, both lobes blunt and incurved. No gemmae. Forming large pure patches ... Sphenolobus saxicola
105B - Olive-green to brown. Medium-sized to large, 1.2-2 mm wide, 1.5-5 cm long. Leaves sub equally bilobed, ventral lobe incurved, dorsal lobe squarrose, lobes acute, spreading from a somewhat sheathing base. Gemmae light red to purplish, 2-celled, on shoots with slightly reduced leaves ... Anastrophyllum michauxii
106A - Plants 0.7-1.2 mm wide, 1-3 cm long, green to golden brown. Leaves pectinate, erect-spreading, deeply concave to channeled. Lobes triangular, dorsal smaller. Gemmae at apices of gradually attenuated shoots, bright red, ± 2-celled. On rock ... Sphenolobus minutum
106B - Plants very small, green to brownish. Leaves sub equally bilobed. Gemmae borne on erect, filiform shoots with reduced leaves -- 107
107A - Dull green to brownish, 0.5-0.9 mm wide, 2-5 mm long. Often consisting entirely of filiform gemmiferous shoots. Gemmae abundant, deep red, 1 -celled, bluntly quadrangular. On logs ... Crossocalyx hellerianus
107B - Clear green, 0 4-0.6 mm wide, 4-6 mm long. Purplish clusters of celled gemmae at tips of filiform shoots. On calcareous rock ... Anastrophyllum tenue
108A - Pure green to olive to yellow-brown, ± reddish, 1.8-2.4 mm wide, 5 cm long. Leaves erect, pectinate, bilobed less than 1/4 their length, rotund to quadrate, sinus rounded, dorsal margin reflexed. Lobes wider than long. Damp to wet rocks ... Marsupella emarginata
108B - Dull green to golden brown, purplish or blackish brown (looking "scorched"). Leaves bilobed less than 1/4 to 1/2 their length. Leaf margins not reflexed -- 109
109A - Plants medium (terrestrial, up to 3 cm long) or large (aquatic, up to 7 cm long), dull green to blackish brown with contrasting pale green young shoots. Leaves as wide as or wider than long, bilobed 1/3 to 1/2. Lobes rounded, suberect to spreading, wider than long. Sinus acute, open to closed. Can be aquatic ... Marsupella sphacelata
109B - Plants small, 0.8-1.5 mm wide, 8-15 cm long, shiny, golden brown to purplish or blackish. Leaves longer than wide, bilobed less than 1/4, lobes triangular, as long as to longer than broad, acute, laxly spreading, sinus open, acute to rectangular. Not aquatic, on wet rock ... Marsupella sparsifolia
110A - Underleaves present -- 111
110B - Underleaves absent (rudimentary ones occasional at shoot tips) -- 120
111A - Underleaves 2-3-lobed, obvious -- 112
111B - Underleaves mostly ovate-lanceolate, occasionally bilobed, smaller -- 115
112A - Rhizoids restricted to bases of bilobed underleaves. Plants translucent, yellowish green or green -- 113
112B - Rhizoids scattered over stem, more abundant near underleaves. Plants opaque -- 114
113A - Medium plants, 1 2-1.5 mm wide, 1-3 cm long, prostrate, sometimes adherent to substrate. Leaves rectangular, lower more deeply bilobed, upper frequently entire to emarginate. Frequently fertile with 3-sided, toothed perianths. Gemmae rare ... Lophocolea heterophylla
[Lophocolea bidentata is similar, but 2.5-3 mm wide, 2-5 cm long, with leaves uniformly bilobed, narrowing towards apex. Rarely fertile.]
113B - Small plants, 0.5-1 mm wide, 1.2-1.8 cm long. Leaves squarish, sinus shallow. Copious spherical gemmae, 1-many-celled, often in masses or filaments on eroded leaf edges. Rarely fertile ... Lophocolea minor
114A - Plants robust, 3-4 mm wide, 4-8 cm long, light green to reddish brown to blackish. Underleaves large, 2-3-lobed, ciliate. Leaves rectangular-ovate, convex. Found in fens ... Mesoptychia rutheana
114B - Plants smaller, 1-1.5 mm wide, 1-2 cm long, dull to yellowish green. Underleaves bilobed, nonciliate, with parallel lobes Habitats various, mesic ... Geocalyx graveolens
115A - Green to chestnut brown to blackish. Shoots long, 5+, 1-2 mm wide, with postical stolons. Leaves distant, ovate, flat, horizontally spreading. Lobes blunt, somewhat asymmetric, sinus shallow, narrow, acute. Underleaves occasional, minute, oblong to bifid. No gemmae. Hygrophytic, usually in bogs ... Odontoschisma fluitans
115B - Leaves usually concave, shallowly but equally bilobed, erect to erect-spreading, touching to overlapping. Underleaves larger, arcuate, occasionally toothed. Habitats various -- 116
116A - Leaves orbicular, sinus acute. Plants fleshy, pellucid light green with reddish ventral stem surfaces and leaf bases, 0.8-1.5 mm wide, 8-15 mm long. On sandy soil ... Nardia insecta
116B - Leaves ovate to lanceolate. Plants opaque, never fleshy. Leaf bases never reddish -- 117
117A - Plants small to medium, light green to brownish, shiny when dry. Leaves ovate, sinus lunate to semicircular. Underleaves large, joined at one side to an adjacent leaf base -- 118
117B - Plants medium to large, green, brownish to blackish or reddish. Underleaves small, 5 cells wide or less at base, free. Obligate calciphytes -- 119
118A - Plants 1-1.3 mm wide, 1-1.5 cm long. Leaves concave, oblong-ovate, oblique, spreading to antically secund, dorsal margin longer than ventral, decurrent. Gemmae rare, 2-celled, on intercalary branches which are usually also androecial. Mainly on rocks ... Harpanthus scutatus
118B - Plants 0.8-1 mm wide, 6-10 mm long Leaves flat to concave, symmetrical. Gemmae common, at tips of gradually attenuated branches, not intercalary, 2-celled, pale green to reddish, elliptical. On rotting logs ... Harpanthus drummondii
119A - Plants opaque, green to golden to reddish brown, 2-2.4 mm wide, 8-15 mm long. Leaves ovate, lobes sharp-pointed. Sinus narrow, acute to obtuse. Cells smallish, with large confluent trigones. Gemmae brown, 1-2-celled, oval, on erect shoots with reduced leaves ... Mesoptychia heterocolpos
119B - Plants fragrant, 1.8-2.8 mm wide (up to 5 mm when fertile), 2-4 cm long, deep green to blackish, never reddish. Leaves quadrate, lobes acute to obtuse. Sinus crescentic to obtuse, or rectangular. Trigones not confluent. Gemmae absent ... Mesoptychia gillmanii
[M. bantriensis; M. collaris will also key here.]
120A - Deep green to brownish black, 0.7-0.9 mm wide, 1-2 cm long. Leaves round, often strongly concave, bilobed 1/4-1/2. Lobes blunt No gemmae. Rudimentary underleaves occasionally present. On wet to moist rocks or over Sphagnum ... Gymnocolea inflata
[Odontoschisma fluitans may also key out here if underleaves are not detected. See couplet 115A.]
120B - Plants never blackish. Leaves ovate to rectangular, never round. Substrates various -- 121
121A - Very small, 0.5-0.9 mm wide, 3-10 mm long. Pellucid, yellowish green to pale green. Leaves broad, flat, rotund, spreading, bilobed 1/4-1/3, shallow sinus. No gemmae. Underleaves occasionally present as stalked slime papillae. Perianth cylindrical and beaked. An obligate calciphile, on damp basic soil on rock ledges ... Mesoptychia badensis
121B - Plants small to medium, opaque Gemmae often present. Perianths not beaked -- 122
122A - Plants small, 0.5-1 mm wide, 5-10 mm long, tightly clumped, green to reddish brown, somewhat fleshy. Leaves imbricate, almost transverse, erect to erect-spreading, becoming erose-lacerate with gemmae production. Leaf cells small and thick-walled. Gemmae abundant. 1 -2-celled, reddish, stellate. Perianths frequent, with fringed decolorate mouths. On acid soils ... Isopaches bicrenata
122B - Plants small to medium. Leaf cells thin-walled, larger. Leaves more distant, not greatly modified by gemmae production. Substrates various -- 123
123A - Plants small, usually erect or suberect. Gemmae abundant. Leaf lobes somewhat elongate (horn-like). Leaves longer than wide -- 124
123B - Plants medium, creeping with ascending tips. Leaves as broad as broader than long Lobes short and broad. Gemmae rare to common -- 125
124A - Pure to dark green, 1.2-1.8 mm wide, 3-20 mm long. Leaves spreading to squarrose, bilobed 1/4-1/3. Gemmae, reddish to yellow-brown, quadrate to trapezoidal. On acid substrates (rocks, logs, etc.) ... Lophoziopsis longidens
124B - Pale yellow-green to reddish or purplish brown, 0.8-1.3 mm wide, 3-8 mm long. Leaves erect-spreading, almost transversely inserted, bilobed 1/3-1/2, lobes lightly rounded. Gemmae angular to stellate, reddish brown. On logs or peaty soil ... Lophozia ascendens
125A - Yellow-brown, 1-3 mm wide, 1-3 cm long, erect in dense patches. Leaves subtransversely inserted, usually imbricate, commonly appressed, nearly orbicular, sometimes antically secund. Lobes subequal; sinus shallow, broadly crescentic. Gemmae green to colorless at shoot tips. In boggy sites ... Lophozia wenzelii
125B - Leaves flat to shallowly concave, lobes not incurved. Sinus deeper, lunate to acute. Gemmae usually present, sparse to abundant, green or red -- 126
126A - Gemmae reddish. Plants ± erect. On rocks or inorganic soil -- 127
126B - Gemmae green. Plants prostrate. Substrates various -- 128
127A - Pure green to brownish or reddish, fleshy, 1.2-1.6 mm wide, 2-3 cm long. Leaves wider than long, oblique, distant, somewhat concave at base, bilobed 1/5 to 1/4, sinus crescentic. Cells large and thin- walled. Gemmae sparse, wine red to purplish. Paroicous, frequently fertile. A pioneer on mineral substrates ... Lophoziopsis excisa
127B - Dull deep green to brown or reddish, rigid, not fleshy, 1.5-2 mm wide, 1-4 cm long Leaves as wide as long, imbricate, very oblique, distinctly concave, bilobed less than 1/5, sinus crescentic to obtuse. Cells smaller, opaque. Gemmae abundant, rust-red to brownish. Dioecious, rarely fertile. Xerophytic on rock or soil over rock ... Barbilophozia sudetica
128A - Green to pale green, stems often reddish, 1-1.5 mm wide, 1-2 cm long. Leaves as wide as long to slightly longer than wide, bilobed 1/2-1/3, often reddish at base, somewhat concave. Lobes acute triangular, sinus rectangulate. Trigones bulging and confluent Gemmae rare. Only on decaying wood ... Lophozia ventricosa var longiflora
128B - Green to yellow-green, 0.8-2 mm wide, 1-2.5 cm long. Leaves wider than long, bilobed less than 1/4, patent, nearly flat. Lobes acute, slightly incurved, sinus lunate to obtuse. Trigones not confluent. Gemmae common. With a wide ecological amplitude ... Lophozia ventricosa
• Adapted from: An Enthusiasts Guide to the Liverworts and Hornworts of Ontario; Linda M Ley, Joan M Crowe; Lakeland University; 1999.
• Genera in red are not known from the Northeast.
The following are some of the genera that have been split since this was originally published:
• Anastrophyllum >> Crossocalyx, Sphenolobus
• Jungermannia >> Liochlaena, Solenostoma
• Lophozia >> Barbilophozia, Isopaches, Lophoziopsis, Mesoptychia, Neoorthocaulis, Obtusifolium, Schistochilopsis, Schljakovia, Tritomaria
Errors or improvements? Email Jeff at info@DigitalNaturalist.info.
last update 2025-Jul-05