Adapted from Syllogeus 62 by Ireland & Bellolio-Trucco. Usage notes at bottom.
1 - Leaves divided into filaments or having margins with many long cilia .... 2
1 - Leaves neither filamentous nor with numerous cilia on margins, entire or broadly lobed, sometimes the lobes ending in a cilium or the leaf base with a few cilia .... 4
2 - Plants small, stems less than 1 mm wide, irregularly branched, leaves divided to base into 3-4 filamentous lobes = Blepharostoma trichophyllum :: On moist decaying logs, damp, shaded rock faces and sometimes on bases of trees.
2 - Plants large, stems usually more than 1 mm wide, pinnately branched, leaves divided into 2-5 lobes, the margins ciliate .... 3
3 - Plants light yellowish- or whitish-green, plumose, usually over 1 cm wide, leaves with narrow lobes with branched cilia = Trichocolea tomentella :: On rocks, soil and rotten logs, predominantly in cedar swamps, but also in rather shady, moist sites, especially beside creeks and waterfalls.
3 - Plants green to reddish- or purplish-brown, usually not plumose, less than 1 cm wide, leaves with broad lobes with unbranched cilia .... PTILIDIUM (2)
A - Leaves divided 1/2 their length into wide lobes, the margins with short cilia; plants green to reddish brown = P.ciliare :: On thin soil or humus over exposed rock, occasionally in depressions in bogs.
A - Leaves divided 3/4 or more their length into narrow lobes, the margins with long cilia; plants green to yellowish brown = P.pulcherrimum :: On bark, at bases of trees, on rotting logs and on rock.
4 - Leaves complicate-bilobed .... 5
4 - Leaves undivided or lobed but not complicate-bilobed .... 10
5 - Leaves with the dorsal lobe smaller than the ventral lobe .... 6
5 - Leaves with the dorsal lobe larger than the ventral lobe .... 7
6 - Leaf lobes narrowly elongate (lingulate), the ventral lobe 2-3 times as long as wide .... DIPLOPHYLLUM (3)
A - Leaves with a vitta extending almost to apex = D.albicans :: Usually on shaded, moist, noncalcareous rocks beside streams, occasionally on rotten wood.
A - Leaves lacking vitta .... B
B - Leaf apices apiculate = D.apiculatum :: On moist soil banks, sometimes on wet rocks near streams. Note - May be confused with Scapania umbrosa but that species has decurrent ventral leaf lobes while D.apiculatum does not.
B - Leaf apices obtuse = D.taxifolium :: On shaded, noncalcareous rock outcrops in humid regions.
6 - Leaf lobes subcircular to broadly ovate, the ventral lobe 1-2 times as long as wide .... SCAPANIA (19)
A - Ventral leaf lobes rounded at apices, the lobes nearly as wide as long .... B
A - Ventral leaf lobes acute at apices, the lobes as wide as long or much longer than wide .... E
B - Ventral leaf lobes not decurrent; leaf margins entire or nearly so = S.irrigua :: In or around standing water in bogs, at margins of lakes and sunny rock pools.
B - Ventral leaf lobes distinctly decurrent; leaf margins dentate to spinose-ciliate, rarely entire .... C
C - Keel of leaves strongly curved; leaf margins entire to weakly dentate; gemmae lacking = S.paludosa :: On rocks in and beside streams or in springy areas of acid bogs.
C - Keel of leaves straight to slightly curved; leaf margins strongly dentate to spinose- ciliate, rarely entire; gemmae often present .... D
D - Stems usually black at maturity; dorsal leaf lobes not decurrent; leaf margins dentate to strongly serrate, rarely entire; gemmae green to yellowish green. = S.undulata :: On acidic rocks in streams or creeks, occasionally on sandy or loamy banks or damp sandstone away from water but in areas of high humidity.
D - Stems green to dark brown or red at maturity rarely black; dorsal leaf lobes distinctly decurrent; leaf margins spinose-ciliate, sometimes dentate; gemmae cinnamon brown = S.nemorea :: On shady, seepy cliffs or ledges, rocks near waterfalls, clayey or loamy soil along paths or banks of streams, occasionally on moist decaying logs.
E - Large plants, usually over 1 cm long; ventral leaf lobes about as wide as long; leaf margins entire or nearly so .... F
E - Small plants, seldom reaching 1 cm long; ventral leaf lobes much longer than wide; leaf margins entire or coarsely and irregularly serrate .... G
F - Keel of leaves straight or slightly curved; gemmae green to yellowish green = S.irrigua (see 6-B)
F - Keel of leaves strongly curved; gemmae reddish to reddish brown = S.paludicola :: In bogs and swamps.
G - Leaf margins coarsely and irregularly serrate = S.umbrosa :: On moist decaying logs or moist rocks near water. Note - Sometimes similar to Diplophyllum apiculatum but that species has nondecurrent ventral leaf lobes while S. umbrosa has decurrent lobes.
G - Leaf margins entire. .... H
H - Leaves dorsally secund, especially when dry, dorsal lobes ca. 1/4 the size of the ventral lobes; gemmae brown to reddish brown = S.gymostomophila :: A calciophile occurring on wet rocks near water.
H - Leaves not dorsally secund, dorsal lobes ca. 1/2 the size of the ventral lobes; gemmae green to yellowish green = S.mucronata :: On soil on acidic or calcareous cliffs and ledges.
7 - Stems without row of underleaves = Radula complanata :: On shaded bark of trees, occasionally on moist rock (also obconica, tenax).
7 - Stems with row of underleaves .... 8
8 - Plants small, stems mostly less than 1 mm wide; underleaves bilobed .... 9
8 - Plants large, stems often over 1 mm wide; underleaves undivided .... PORELLA (2)
A - Underleaves narrow, about the same width as stem, margins plane; plants hygrophytic = P.pinnata :: On rocks and logs in streams or sometimes on bases of trees and stumps subjected to flooding.
A - Underleaves broad, wider than the stem, margins reflexed; plants xerophytic = P.platyphylla :: On shaded hardwood trees, occasionally on rock.
9 - Plants yellowish green; ventral leaf lobes neither helmet-shaped not attached to stem by stalk = Lejeunea cavifolia :: On shaded rock and bark of trees, rarely on marly soil (also lamacerina).
9 - Plants reddish brown or dark green; ventral leaf lobes helmet-shaped, attached to stem by slender stalk .... FRULLANIA (11)
A - Dorsal leaf lobes with an oblique line of ocelli = F.asagrayana :: On rocks, cliffs or tree trunks and limbs.
A - Dorsal leaf lobes without line of ocelli .... B
B - Plants with some erect, nearly naked stem and branch tips due to caduceus leaves = F.bolanderi :: On tree trunks or rarely on dry cliffs.
B - Plants without erect, naked stem and branch tips .... C
C - Ventral leaf lobes large, more than half the size of the dorsal leaf lobes; dorsal leaf lobes truncate at base = F.oakesiana :: On tree trunks (often Thuja) mostly in swamps or boggy areas.
C - Ventral leaf lobes small, scarcely reaching 1/3 the size of the dorsal leaf lobes; dorsal leaf lobes cordate or auriculate at base .... D
D - Underleaves without lateral teeth = F.eboracensis :: On tree trunks (primarily deciduous), occasionally on bare rock.
D - Underleaves usually with lateral teeth = F.brittoniae :: On trunks of deciduous trees, rarely on rock.
10 - Underleaves present .... 11
10 - Underleaves absent .... 22
11 - Leaves incubous .... 12
11 - Leaves succubous or transverse .... 14
12 - Leaves with 3-4 teeth or lobes .... 13
12 - Leaves entire or retuse at apex .... CALYPOGEIA (7)
A - Underleaves distinctly bilobed, the sinus descending 1/3-1/4 their length = C.muelleriana :: On soil, humus, peaty soil or over rocks in damp, shaded sites.
A - Underleaves entire or retuse at apex .... B
B - Leaves narrowly rounded at apex = C.integristipula :: On mineral soils and organic substrata in coniferous swamps, sometimes on shaded cliffs in woods.
B - Leaves truncate to truncate-retuse at apex = C.neesiana :: On Sphagnum or other organic substrata, e.g., badly decayed stumps and logs, humus, and peat; sometimes on loamy soil.
13 - Plants large, stems 3-6 mm wide, ventral flagella present; leaves tridentate = Bazzania trilobata :: On shaded banks, wet rotten logs and stumps, acidic rocks and bases of trees in moist, shaded woods and swamps (also denudata, tricrenata).
13 - Plants small, stems 1-2 mm wide, ventral flagella lacking; leaves 3-4 lobed into finger-like segments = Lepidozia reptans :: On humus, decaying wood, peaty soil and soil over rock in moist, deeply shaded woods.
14 - Leaves entire or somewhat retuse at apex .... 15
14 - Leaves 2-4 lobed .... 16
15 - Underleaves entire, lanceolate = Mylia anomala :: Over Sphagnum in peat bogs and on moist ledges (also taylori).
15 - Underleaves bilobed, often with a tooth on the base of the lobes .... CHILOSCYPHUS (2)
A - Plants whitish green; leaves rounded- truncate to truncate, sometimes retuse at apex; sporophytes frequent = C.pallescens :: On moist soil, rocks, decaying logs and humus near streams and swamps. C.pallescens var fragilis is aquatic.
A - Plants green to dark green; leaves rounded to rounded-truncate, seldom retuse at apex; sporophytes rare = C.polyanthus :: Usually on soil or humus over noncalcareous rocks beside streams or ponds. C.polyanthus var rivularis is aquatic.
16 - Leaves 3-4 lobed .... 17
16 - Leaves 2, rarely 3, lobed .... 18
17 - Leaves with deeply channeled lobes, the margins broadly reflexed = Tetralophozia setiformis :: On dry, granitic rock or on ground between boulders.
17 - Leaves without channeled lobes and reflexed margins .... BARBILOPHOZIA (8)
A - Leaves mostly 3-lobed, rarely 4-1obed; numerous, erect flagellae arising from stem apices = B.attenuata :: On boulders, cliff faces and ledges and decaying logs and stumps.
A - Leaves mostly 4-lobed, rarely 3-lobed; flagellae lacking .... B
B - Leaves acute to obtuse, never mucronate tipped, lacking cilia; underleaves small and indistinct = B. barbata :: Usually on acidic cliff face and ledges, sometimes on boulders, rarely on rotting logs, mainly in coniferous forests.
B - Leaves usually mucronate tipped, the postical leaf base with cilia; underleaves large and distinct .... C
C - Plants green or brownish, leaves flat or weakly crisped, middle leaf lobe about as broad as long; reddish brown gemmae often present at shoot apices = B.hatcheri :: Predominantly on acidic cliff faces and ledges, sometimes on boulders, in spruce-fir woods.
C - Plants whitish or yellowish green, leaves strongly undulate-crispate, middle leaf lobe about twice as broad as long; gemmae lacking = B.lycopodioides :: On acidic cliff faces and ledges, boulders, sometimes on humus over calcareous rock in spruce-fir woods.
18 - Leaves distant, flat, the lobes obtuse or broadly rounded at apex; plants occurring in Sphagnum bogs or in other acidic, subaquatic habitats = Odontoschisma fluitans :: In and beside standing pools of water in peat bogs (also francisci).
18 - Leaves mostly close, usually somewhat concave, the lobes acute to narrowly obtuse at apex; plants occurring mostly in drier habitats .... 19
19 - Underleaves entire, attached on one side of base of lateral leaves = Harpanthus scutatus :: Often on siliceous rocks, more rarely on moist decayed logs, humus and peaty soil in damp, shaded sites (also drummondii, flotovianus).
19 - Underleaves bilobed or ciliate, rarely entire, not attached to lateral leaves .... 20
20 - Underleaves bifid nearly to base, the margins without cilia = Geocalyx graveolens :: On humus or peaty soil, moist, decaying wood, on mineral soil, or on thin soil over rocks.
20 - Underleaves bifid, divided 1/2-2/3 their length, usually ciliate, or underleaves entire .... 21
21 - Rhizoids confined to bases of underleaves; underleaves ciliate .... LOPHOCOLEA (4)
A - Plants small, 0.5-1.0 mm wide, usually sterile, clusters of yellowish green gemmae on margins of leaves = L.minor :: Common on loamy soil banks, in crevices of calcareous shales and sandstones, and on moist rotten logs.
A - Plants large, 1-2 mm wide, usually fertile and perianths present, gemmae 1acking = L.heterophylla :: Commonly on decaying wood but also on organic substrate, such as tree bases and peat in old dried out bogs; sometimes on moist soil along streams, and on damp racks.
21 - Rhizoids scattered throughout ventral surface of stems; underleaves sometimes entire .... LOPHOZIA, LOPHOZIOPSIS, MESOPTYCHIA, SCHISTOCHILOPSIS (24)
A - Plants with underleaves .... B
A - Plants lacking underleaves .... C
B - Underleaves ciliate; gemmae lacking = Mesoptychia rutheana :: A calciophile occurring on wet ground in cedar swamps and rich fens.
B - Underleaves entire; gemmae usually present, brownish, on leaf margins at tips of gemmiferous shoots = Mesoptychia heterocolpos :: On calcareous rocks or rarely on decaying logs.
C - Leaf lobes toothed = Schistochilopsis incisa :: An acidophile, on moist, decaying logs, peaty banks, humus-covered rocks, or sometimes on bare, moist rocks.
C - Leaf lobes entire .... D
D - Leaves about as wide long, the sinus broad and shallow; gemmae greenish or yellowish green = Lophozia ventricosa :: On moist, shaded racks, decaying logs and peaty soil.
D - Leaves much longer than wide, the sinus narrow and deep; gemmae orange or reddish brown = Lophoziopsis longidens :: On acidic rocks, decaying wood and bases of trees.
22 - Leaves undivided or nearly so .... 23
22 - Leaves 2-4 lobed .... 26
23 - Rhizoids purple or violet; leaves wavy or ruffled when dry = Fossombronia foveolata :: On damp, sandy soil at lake margins and beside streams (also cristula, salina, wondraczekii).
23 - Rhizoids not purple or violet, usually hyaline or brownish; leaves not wavy or ruffled when dry .... 24
24 - Leaves usually with serrated margins = Plagiochila porelloides :: On moist rocks and shaded, soil-covered banks, rarely on rotten logs, stumps and bases of trees (also austinii).
24 - Leaves with entire margins (female bracts sometimes ciliate) .... 25
25 - Plants green to reddish brown; female bracts ciliate at base; perianth tapered to a ciliate mouth; common, on rotten wood, soil or rocks, never in streams = Syzygiella autumnalis :: Usually on decaying logs or acidic rocks, sometimes on shaded banks and occasionally on bases of trees.
25 - Plants green or some plants reddish with a border of enlarged cells; female bracts entire; perianths truncate or tapered, the mouth entire; infrequent, on rotten wood, soil or rocks, sometimes in streams .... JUNGERMANNIA, LIOCHLAENA, SOLENOSTOMA (8)
A - Leaves with a distinct border of large, swollen cells = Solenostoma gracillimum :: On sandy, loamy or clayey banks.
A - Leaves lacking border of enlarged cells .... B
B - Leaves oblong-oval, often slightly retuse at apex; perianth truncate at apex; plants mostly in mesic habitats = Liochlaena lanceolata :: On moist rock, on soil over rock, on decaying logs and on peaty ground in boggy areas.
B - Leaves cordate to nearly rounded, not retuse at apex; perianth tapered at apex; plants in aquatic habitats = Jungermannia exsertifolia :: On rocks in or beside silt-free streams.
26 - Leaves 3-4 lobed .... 27
26 - Leaves 2 lobed .... 29
27 - Leaf lobes all about the same size .... BARBILOPHOZIA (see 17)
27 - Leaf lobes unequal in size, the dorsal lobe much shorter than the ventral lobe .... 28
28 - Leaf lobes entire; gemmae reddish brown, sometimes lacking .... TRITOMARIA (6)
A - Leaves as wide or wider than long; gemmae lacking = T.quinquidentata :: On basic rock outcrops and around rock pools.
A - Leaves longer than wide; gemmae usually present, reddish brown = T.exsectiformis :: On decaying logs and peaty soil over acidic cliffs.
28 - Leaf lobes toothed; gemmae green or yellowish green, usually present .... LOPHOZIA (see 21)
29 - Leaves strongly concave and sac-like, each lobe ending in a long, slender cilium; occurring only on rotten wood. = Nowellia curvifolia :: On moist decaying logs.
29 - Leaves neither sac-like nor ending in long cilia; on wood and other substrates .... 30
30 - Leaves transverse .... 31
30 - Leaves succubous .... 32
31 - Leaves deeply divided, 1/3-1/2 their length; gemmae usually present, reddish or purplish brown .... ANASTROPHYLLUM, CROSSOCALYX, SPHENOLOBUS (4)
A - Plants small, gemmiferous shoots filiform, 0.5-1.5 mm wide = Sphenolobus minutus :: On peaty soil, often among mosses and on damp, shaded rocks.
A - Plants larger, gemmiferous shoots not filiform, 1.0-2.5 mm wide = Anastrophyllum michauxii :: On acidic cliff faces and ledges, sometimes on decaying logs.
31 - Leaves shallowly divided, 1/8-1/3 their length; gemmae lacking .... MARSUPELLA (6)
A - Leaves weakly bilobed, the sinus shallow and broad, extending about 1/5 the leaf length, dorsal margin distinctly reflexed = M.emarginata :: On moist, acid rocks beside streams. M.emarginata var aquatica is aquatic.
A - Leaves strongly bilobed, the sinus deep and narrow, extending about 1/3 the leaf length, dorsal margin plane = M.sphacelata :: On acidic rocks and cliffs in and along streams, sometimes on dry, sunny cliffs.
32 - Leaf lobes obtuse to broadly rounded .... 33
32 - Leaf lobes acute to acuminate .... 34
33 - Leaves somewhat concave, about as broad as long, the lobes about equal in size = Gymnocolea inflata :: On humus over wet to moist, acidic racks and rock outcrops, or sometimes in depressions in bogs.
33 - Leaves flat, much longer than broad, the ventral lobe larger than the dorsal lobe = Odontoschisma fluitans (see 18)
34 - Plants large, mostly over 1 mm wide, stems opaque; leaves shallowly cleft, without connivent lobes = LOPHOZIA see 21
34 - Plants small, usually 0.5-1.0 mm wide, stems transparent; leaves deeply cleft, the lobes often connivent .... CEPHALOZIA & FUSCOCEPHALOZIOPSIS (9)
A - Leaves deeply divided, the sinus extending 1/2 or more the leaf length, the lobes nonconnivent = Cephalozia bicuspidata :: On moist, acid rocks, mineral soil and peaty or sandy banks beside streams, sometimes on decaying logs.
A - Leaves more shallowly divided, the sinus extending less than 1/2 the leaf length, the lobes usually connivent = Fuscocephaloziopsis lunulifolia :: Most often on decaying wood and in peat bogs, but also on moist rock, in soil-filled rock crevices and on soil banks.
:: This has been adapted from "Syllogeus 62 - Illustrated Guide to Some Common Liverworts, Hornworts, and Mosses of Eastern Canada" by Ireland & Bellolio-Trucco (1987). An original is available from Biodiversity.org.
:: If your selected statement ends in an all capitalized colored genus, a subkey with alphabetical enumeration follows. This is the format the original used and I've kept it.
:: The number in parenthesis is the total number of species per Liverworts of New England by Lincoln and includes rare species and historical reports. Only the more common species are keyed above.
:: Taxonomy has changed since the publication of this excellent key. I am continually in the process of trying to make sense of the current state of liverwort taxonomy and updating this key appropriately. Referenced suggestions always welcome!
:: All of these species are found in the northeast. Many are found elsewhere in North America. Consult the original for detailed ranges.
Errors, improvements or suggestions? Email info@DigitalNaturalist.INFO.
last update 2025-Jun-06