by Blanka Aguero based on the references below
Pilous, Zdeněk, and J. Duda. 1960. Klíč k Určování Mechorostu CSR. Nakladatelství Československé Akademie Věd Praha. 569 pages, 94 figures.
Hicks, Marie L. 1992. Guide to the Liverworts of North Carolina. Duke University Press Durham and London 1992. [v] + 239 pages, 120 figures, 154 maps.
1a - Rhizoids of two kinds: smooth and pegged -- 2
1b - Rhizoids only smooth -- 9
2a - Thallus star-like or swimming in water; capsules buried in the thallus -- 3
2b - Thallus ribbon-like, not swimming; sporophytes on receptacles -- 4
3a - Ventral scales dark violet, long, dentate; some cells with oil bodies ... Ricciocarpus natans
3b - Ventral scales small; cells without oil bodies ... Riccia [10]
4a - Air pores simple -- 5
4b - Air pores barrel-shaped in cross-section -- 8
5a - Thallus surface with lunate gemmae cups ... Lunularia cruciata
5b - Thallus surface without gemmae cups -- 6
6a - Air pores visible without hand lens, thallus surface divided into fields (snakeskin-like texture) ... Conocephalum salebrosum
6b - Air pores not prominently visible, thallus surface not markedly divided into fields -- 7
7a - Air pores surrounded by 4-5concentric circles of cells; white hairy scales at base of stalk and under receptacles; antheridia in reniform pad at posterior base of stalk; oil cells absent in thallus ... Reboulia hemisphaerica
7b - Air pores not so differentiated; hairy scales not present but white strap-like segments of pseudoperianth developed around each capsule on underside of receptacles; antheridia in papillae posterior to base of stalk; oil cells present in thallus ... Asterella tenella
8a - Thallus surface with rounded gemmae cups; thallus green or blackish below; female receptacles deeply divided in 7-10 lobes ... Marchantia polymorpha
8b - Thallus surface without gemmae cups; thallus reddish on ventral side; female receptacles with 4 shallow lobes ... Marchantia (Preissia) quadrata
9a - Thallus cells with one chloroplast containing a pyrenoid ... hornworts [5]
9b - Thallus cells with multiple chloroplasts without pyrenoids -- 10
10a - Thallus with dark spots of Nostoc in mucilage chambers; thallus with lobes; star-shaped gemmae or flask-shaped gemmae containers usually present ... Blasia pusilla
10b - Thallus without Nostoc colonies, without star-shaped gemmae or flask-shaped gemmae containers -- 11
11a - Thallus with sharply delimited midrib and with marginal hairs ... Metzgeria [4]
11b - Thallus without midrib or midrib not sharply delimited, without marginal hairs -- 12
12a - Sporophytes and antheridia form laterally, sporophytes surrounded by fleshy involucre; elaters attached to tips of capsule valves -- 13
12b - Sporophytes arising from dorsal flap or dorsal notch; elaters attached to base of capsule -- 14
13a - Thallus without apparent midrib, plants small ... Riccardia [4]
13b - Midrib continuously changing to wings, plants large (5-10mm wide) ... Aneura pinguis, sharpii
14a - Midrib with central strand of narrow elongated cells; antheridia dorsal in two rows, one on each side of the midrib, covered by scale ... Pallavicinia lyelii
14b - Midrib without central strand, antheridia not arranged in 2 rows -- 15
15a - Antheridia covered by scale and scattered on dorsal surface ... Moerckia flotoviana
15b - Antheridia in pustules along the dorsal midrib ... Pellia [2]|Apopellia[2]
1a - Stems with 3 rows of leaves of equal size ... Haplomitrium hookeri
1b - Stems with 2 rows of leaves, ventral leaves reduced if present -- 2
2a - Leaves irregularly lobed or coarsely serrate or undulate ... Fossombronia [4]
2b - Leaves serrate ... Plagiochila austinii, porelloides
2c - Leaves entire -- 3
3a - Underleaves apparent -- 4
3b - Underleaves missing -- 9
4a - Leaves incubous ... Calypogeia [7]
4b - Leaves succubous -- 5
5a - Underleaves entire -- 6
5b - Underleaves bilobed -- 8
6a - Mid-leaf cells 40-50 X 60-100 µ ... Mylia anomala, taylori
6b - Mid leaf cells 25-50 µ -- 7
7a - Mid leaf cells 25-30 µ ... Syzygiella autumnalis
7b - Mid leaf cells 30-50 µ ... Nardia [3]
8a - Underleaves deeply divided, often with one lateral tooth ... Chiloscyphus pallescens, polyanthos*
8b - Underleaves thread-like, tiny or missing calcareous species ... Pedinophyllum interruptum
9a - Perianth almost completely covered by bracts ... Solenostoma (Plectocolea) [5]
9b - Free perianth exserted above bracts -- 10
10a - Perianth flattened ... Pedinophyllum interruptum
10b - Perianth oval, tubular or cylindrical -- 11
11a - Archegonia on short lateral branches ... Odontoschisma [4]
11b - Archegonia at the end of main stems or their branches -- 12
12a - Leaves lingulate ... Jungermannia [3]
12b - Leaves rounded, cordate or oval -- 13
13a - Underleaves lanceolate, sometimes missing; female bracts with one tooth at base or ciliate ... Syzygiella autumnalis
13b - Underleaves always missing; female bracts entire ... Solenostoma [7]
(including leaves with ventral lobe in shape of cup, sack, helmet, etc.)
1a - Leaves succubous or transversely inserted; if complicate bilobed then dorsal lobe is always smaller or at most of equal size as the lower lobe -- 2
1b - Leaves incubous; if complicate bilobed then dorsal lobe is always larger than ventral lobe -- 24
2a - Leaves keeled -- 3
2b - Leaves not keeled -- 4
3a - Ventral lobe lingular, 3-4 times longer than wide ... Diplophyllum [4]
3b - Ventral lobe not lingular, 1-3times longer than wide ... Scapania [7]
4a - Leaves transversely inserted -- 5
4b - Leaves obliquely inserted -- 16
5a - Leaves all around with cilia ... Ptilidium ciliare, pulcherimum
5b - Leaves without cilia -- 6
6a - Ventral leaf margin forms a sack, leaf lobes attenuated into ciliate tips ... Nowellia curvifolia
6b - Leaves of different shape -- 7
7a - Underleaves present -- 8
7b - Underleaves absent -- 11
8a - Underleaves usually small, plants very small ... Cephaloziella [9]
8b - Underleaves almost as large as lateral leaves -- 9
9a - Plants julaceous, leaf cells 20-30 µ, arctic/alpine -- 10
9b - Plants not julaceous, leaf cells 30-70 µ ... Hygrobiella laxifolia
10a - Underleaves undivided ... Fuscocephaloziopsis (Pleurocladula) lunulifolia, macrostachya
10b - Underleaves bilobed ... Anthelia juratzkana
11a - Plants worm-like, in tightly closed cushions, leaf tips hyaline, subalpine/alpine ... Gymnomitrion concinnatum, coralloides
11b - Plants not in tight cushions, leaves without hyaline tips -- 12
12a - Leaves transverse -- 13
12b - Dorsal leaf lobe transversely inserted, ventral lobe inserted in an angle -- 14
13a - Oil bodies large, 2-3 per cell, underleaves and gemmae always missing ... Marsupella [6]
13b - Oil bodies tiny, underleaves and gemmae are sometimes present ... Cephaloziella [9]
14a - Sterile plants barely 0.2 mm wide; female bracts coarsely dentate ... Crossocalyx hellerianus
14b - Plants 1-3 mm wide; female bracts entire or with rare teeth -- 15
15a - Leaves sometimes somewhat keeled; leaf cells thin-walled or with uniformly thickened walls and corners ... Sphenolobus minutus, saxicola
15b - Leaves concave, clasping the stem; leaf cells with thickened walls and triangular/knot-like corner thickenings ... Anastrophyllum michauxii
16a - Underleaves present -- 17
16b - Underleaves absent -- 23
17a - Leaf lobes blunt or rounded -- 18
17b - Leaf lobes acute -- 20
18a - Leaf lobe incision up to 1/5-1/4 of leaf length ... Odontoschisma fluitans, francisci
18b - Leaf lobe incision deeper, up to 1/3-1/2 of leaf length -- 19
19a - Underleaves tiny, lanceolate, or missing; leaf lobe incision in sharp angle ... Gymnocolea inflata
19b - Underleaves usually with some cilia or teeth on margin; leaf lobe incision in 90 degree angle ... Obtusifolium obtusum
20a - Ventral branching -- 21
20b - Lateral branching -- 22
21a - Underleaves undivided ... Harpanthus [3)
21b - Underleaves deeply divided ... Geocalyx graveolens
22a - Leaf cells thin-walled, without corner thickenings ... Lophocolea [4]
22b - Leaf cells with triangular corner thickenings ... Mesoptychia (Leiocolea) [6]
23a - Female reproductive structures terminal on main stems or branches -- Key E Lophoziaceae
23b - Female reproductive structures on short ventral branches ... Cephalozia[3]|Fuscocephaloziopsis [5]
24a - Leaves not differentiated into dorsal and ventral lobe -- 25
24b - Leaves with large dorsal lobe and smaller ventral lobe -- 26
25a - Plants with flagelliform ventral branches ... Bazzania [3]
25b - Plants without flagelliform ventral branches ... Calypogeia [7]
26a - Underleaves absent -- 27
26b - Underleaves present -- 28
27a - Leaf cells (at least on the dorsal lobe) with projecting papillae ... Cololejeunea biddlecomiae
27b - Leaf cells smooth ... Radula [3]
28a - Ventral leaf lobe is connected to the dorsal lobe by visible keel -- 29
28b - Ventral leaf lobe is connected to the dorsal lobe by only a small narrow connection -- 30
29a - Ventral leaf lobe is about 1/5 of the dorsal lobe ... Lejeunea cavifolia, lamacerina
29b - Ventral leaf lobe is about 1/2 smaller than dorsal lobe ... Microlejeunea ulicina
30a - Plants usually green; ventral leaf lobe flat or with margin recurved ... Porella pinnata, platyphylla
30b - Plants usually brown to red-brown; ventral leaf lobe forming cup/bell/sack ... Frullania [11]
1a - Leaves irregularly lobed or carved, curly ... Fossombronia [4]
1b - Leaves different -- 2
2a - Leaves with many cilia or hairs -- 3
2b - Leaves without hairs or cilia, or these only at the lower end of the leaf margin -- 4
3a - Leaves with 2 lobes, the lower lobe is again divided; all around with simple cilia ... Ptilidium ciliare, pulcherimum
3b - Leaves deeply divided into 4 narrow lobes, with many thin usually divided cilia ... Trichocolea tomentella
4a - Leaves divided all the way to the base into 3-4 lobes -- 5
4b - Leaves divided at most up to 3/4 the way to the base into 3-4 lobes -- 7
5a - Leaf lobes consisting of only 1 row of cells ... Blepharostoma trichophyllum
5b - Leaf lobes consisting of multiple cell layers (at least at base) -- 6
6a - Leaf lobes broadly lanceolate, stiff, at base roughly dentate ... Tetralophozia setiformis
6b - Leaf lobes narrow, with only 2-3 cells at base, entire ... Kurzia pauciflora, sylvatica
7a - Lower leaf margin with cilia ... Barbilophozia|Orthocaulis|Neoorthocaulis
7b - Lower leaf margin without cilia -- 8
8a - Underleaves present obvious -- 9
8b - Underleaves missing -- 11
9a - Leaves succubous ... Barbilophozia|Neoorthocaulis
9b - Leaves incubous -- 10
10a - Leaves half-way divided into 3-4 lobes ... Lepidozia reptans
10b - Leaves shallowly 2-3 lobed ... Bazzania [3]
11a - Leaves obliquely inserted, symmetrical ... Barbilophozia|Orthocaulis|Neoorthocaulis
11b - Lower(front) leaf margin transversally inserted, upper(back) leaf margin obliquely inserted ... Tritomaria [6]
(as understood in 1950s, and referred to by key above)
1a - Leaves with 3-4 lobes -- 2
1b - Leaves with 2 (rarely 3) lobes -- 8
2a - Leaves stiff, divided up to base ... Tetralophozia setiformis
2b - Leaves at most divided to 3/4 -- 3
3a - Lower leaf margin with cilia ... Barbilophozia s.lat
3b - Lower leaf margin without cilia -- 4
4a - Underleaves present ... Barbilophozia s.lat
4b - Underleaves absent -- 5
5a - Leaves obliquely inserted -- 6
5b - Lower (front) leaf margin transversally inserted, upper(back) leaf margin obliquely inserted ... Tritomaria
6a - Oil bodies 30-50 per cell ... Tritomaria capitata, laxa
6b - Oil bodies 4-8 per cell ... Barbilophozia s.lat
8a - Leaves at least by lower (front) margin transversally attached -- 9
8b - Leaves completely obliquely inserted -- 12
9a - Sterile plants up to 0.5 mm wide; On wood ... Crossocalyx hellerianus
9b - Sterile plants 1-3 mm wide -- 10
10a - Plants with underleaves ... Schljakovia kunzeana
10b - Underleaves absent -- 11
11a - Leaves weakly keeled ... Sphenolobus minutus, saxicola
11b - Leaves not keeled ... Anastrophyllum michauxii
12a - Underleaves present -- 13
12b - Underleaves absent -- 15
13a - Leaf lobes blunt -- 14
13b - Leaf lobes acute or almost acute ... Mesoptychia (Leiocolea) [6]
14a - Underleaves large, bilobed ... Obtusifolium obtusum
14b - Underleaves minute, simple, or missing ... Gymnocolea inflata
15a - Walls of leaf cells uniformly thick ... Isopaches bicrenatus
15b - Walls of leaf cells thin -- 16
16a - Leaf lobes usually blunt ... Gymnocolea inflata
16b - Leaf lobes acute or acutish -- 17
17a - Calciphile; perianth smooth, below mouth contracted to a tube ... Mesoptychia badensis
17b - Usually calciphobe; perianth only plicate at mouth ... Lophozia
Numbers in [] after a genus is the number of species if more than two.
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last update 2026-Apr-14