LOPHOCOLEACEAE VANDEN BERGHEN

Thouvenot, Louis, 2023, A taxonomic revision of the Lophocoleaceae Vanden Berghen (Marchantiophyta) of New Caledonia, Cryptogamie, Bryologie 20 (1), pp. 1-60 : 4-6

KEY TO NEW CALEDONIAN SPECIES OF LOPHOCOLEACEAE VANDEN BERGHEN AND SELECTED TAXA RECENTLY TRANSFERRED TO OTHER FAMILIES

1. Basal parts of the leaves with pouches made of expanded or incurved parts of the lamina ............................. 2

— Leaves without pouches ................................................................................................................................ 3

2. Each pouch formed by the incurved basal margin of a single leaf or underleaf; underleaves without linear lobes; leaves widely ovate with shortly toothed margins ............................... Tetracymbaliella Grolle (Brevianthaceae)

— Each pouch formed by two successive leaves, the dorsally enlarged base of a leaf set above the previous one; underleaves with spreading linear lobes; leaves rectangular in outline, entire margined, the apices deeply bifid ............................................ Otoscyphus crassicaulis (Steph.) J.J.Engel, Bardat & Thouvenot (Lophocoleaceae)

3. Plants brownish; leaf cells mammillose, with large contiguous spheroid trigones; underleaves reniform-rounded superficially toothed .......................... Conoscyphus trapezioides (Sande Lac.) Mitt. ex Schiffn. (Acrobolbaceae)

— Plants green, rarely red tinged; leaf cells smooth, rarely bulging or papillose, with trigones null to large and rarely contiguous; underleaves of various shapes ..................................................................................................... 4

4. Plants light green usually red tinged; underleaves vestigial or very small, narrower than the stem, and bifid with linear lobes, made of up to three short cells; fertile plants with a long cylindrical marsupium at the end of the fertile shoots ................................... Goebelobryum unguiculatum (Hook.f. & Taylor) Grolle (Acrobolbaceae)

— Plants green when fresh, without red pigment; underleaves usually well developed, at least as wide as the stem; fertile plants without a marsupium .............................................................. Lophocoleaceae Vanden Berghen

5. Leaves subopposite and underleaves connate to both nearest leaves, connation usually wide ......................... 6

— Leaves alternate, rarely subopposite, with underleaves at most narrowly connate to one of the nearest leaves or free on both sides ....................................................................................................................................... 23

6. Gynoecia and androecia terminal on main shoots or long leaved branches; leaves asymmetrically oblong with the ventral base widened, leaf apices with 1-2 sharp lobes, lateral margins sharply toothed or not; underleaves ovate or reniform, shortly bifid and more or less toothed all around ............................................................. 7

— Gynoecia and androecia terminal on short leafless ventral-lateral branches; leaves and underleaves of various shapes ........................................................................................................................................................... 8

7. Normal leaves canaliculate, gradually narrowing from base to apex; lateral margins of leaves and underleaves usually toothed; leaf cells with strong trigones ........................ Cryptolophocolea subcostata (Steph.) Thouvenot

— Normal leaves convex, ovate oblong to lingulate, the apex somewhat narrower; lateral margins of leaves usually naked or with a few teeth; lateral margins of underleaves with at most a single tooth on both sides; leaf cells without trigones ....................................................... Cryptolophocolea explanata (Mitt.) Váňa & Crand. -Stotl.

8. Leaves entire or with the rounded apices superficially retuse but in a few shoots some of the leaves may be shortly bifid ............................................................................................................................................................. 9

— Leaves lobed, toothed or ciliate-laciniate, or at least with a small tooth at both angles of truncate apices .... 16

9. Underleaves widely reniform, the apices entire, margins with a few scattered small teeth; leaves entire except small teeth at the base of the dorsal margins ................................ Heteroscyphus diestianus (Sande Lac.) Piippo

— Underleaves reniform or not, the apices at least superficially bifid, margins variously ornamented; leaves never with teeth restricted to the base of the dorsal margin .................................................................................. 10

10. Leaves asymmetrically oval acuminate ............. Heteroscyphus subacuminatus (Herzog) Thouvenot , comb. nov.

— Leaves of various shapes, rounded, ovate or oblong, never acuminate ......................................................... 11

11. Underleaves shortly bifid with margins densely toothed all around ................................................................. ......................................................................................... Heteroscyphus splendens (Lehm. & Lindenb.) Grolle

— Underleaves more conspicuously bifid with margins remotely toothed or laciniate ..................................... 12

12. Leaves oblong; cells without trigones or with nodulose trigones ................................................................. 13

— Leaves widely ovate to rounded; cells with large nodulose or truncate trigones ........................................... 15

13. Plants large, up to 5 mm wide; underleaves reniform in outline with lateral margins laciniate .................... 14

— Plants smaller, up to 3.8 mm wide; underleaves ovate to sub-reniform with lateral margins remotely toothed .......................................................................... Heteroscyphus supinopsis J.J.Engel, Thouvenot & Frank Müll.

14. Plants fleshy; leaves dorsally free; cells without trigones .................... Heteroscyphus succulentus (Gott.) Schiffn.

— Plants rigid; leaves dorsally connate; cells with nodulose trigones .... Heteroscyphus deplanchei (Steph.) Schiffn.

15. Plants medium sized; leaves ovate, entire, up to 1.6 mm long; underleaves bifid with acute triangular lobes and shortly toothed margins ............................................................ Heteroscyphus kanakensis Thouvenot & Engel

— Plants large; leaves rounded, apices retuse, 1.5-3 mm long; underleaves bifid with lanceolate lobes and laciniate margins ................................................................................................. Heteroscyphus giganteus (Steph.) Hürl.

16. Leaves rounded, bifid, lobes short, narrow, acute, margins entire to superficially toothed; underleaves wide, rounded, bifid to 4-fid, margins toothed; cells with large nodulose trigones ............................................... 17

— Leaves either oblong to rectangular with various apices, or rounded to oval with long toothed-ciliate margins; underleaves various; cells with minute to large trigones .............................................................................. 18

17. Leaves asymmetrically bifid with dorsal margins straight or slightly convex, usually strongly recurved, ventral margins widely rounded, bifid apices shifted toward the upper dorsal margins; leaf and underleaf lobes usually acuminate with long linear apices .......................... Heteroscyphus aselliformis (Reinw., Blume & Nees) Schiffn.

— Leaves symmetrically bifid with both margin curvatures similar and sinus set on the top of the rounded apex; leaf and underleaf lobes triangular acute, if acuminate, then with shorter apices ............................................. ...................................................................................................... Heteroscyphus confertus (Steph.) Thouvenot

18. Leaves rounded to ovate, apices rounded or widely triangular with three long ciliate processes, triangular at base; margins usually with few to numerous cilia restricted to subapical and ventral parts; underleaves transversely elongate, 2-3 times as wide as the stem, bifid, lobes like the leaf appendages single or furcate, each lateral margins variously toothed to lobate ciliate ............................................... Heteroscyphus grandiflorus (Steph.) Hürl.

— Leaves elongate, oval-oblong to ovate trapezoid or rectangular, apices various, if rounded then with small teeth, if triangular then teeth spinose, not ciliate; margins entire except near apices or with a tooth more on ventral margins; underleaves various ...................................................................................................................... 19

19. Shoots canaliculate with the leaves dorsally assurgent, the abaxial surface of opposite leaves facing one another; leaves ovate trapezoid; leaf cell walls strongly thickened, with one thin pore on each side of the cells .............. ................................................................. Heteroscyphus assurgentissimus J.J.Engel, Thouvenot & Frank Müll.

— Shoots complanate with the leaves spreading out, the abaxial surfaces flat or convex, not facing to the opposite ones; leaves oblong to lingulate; leaf cell walls thin, with or without trigones ............................................. 20

20. Underleaves transversally elongate in outline, bifid with triangular lobes acuminate and widely divergent, one or two small teeth on both lateral margins .................................................................................................. 21

— Underleaves either reniform with 4-6 subequal teeth or bifid with margins heavily lobate-laciniate ............ 22

21. Leaf cells without trigones; leaf apices widely rounded to truncate, rarely acute, with 4-6 or more sharp teeth, roughly equal; underleaf lateral margins with one tooth on both sides ............................................................ ................................................................................... Heteroscyphus argutus (Reinw., Blume & Nees) Schiffn.

— Leaf cells with large nodulose trigones; leaf apices truncate, concave, with a single tooth at both angles; underleaf lateral margins with two teeth on both sides ...................................................... Chiloscyphus longifissus Steph.

22. Underleaves strongly narrowed below and so narrowly decurrent and connate to the leaves by a band up to five cells wide; leaf cells with large nodulose trigones; leaves ovate-lingulate with apices variously shaped in a same shoot, entire rounded, or acute to bifid, or acute with 1-2 subapical teeth so that the leaf apices seem bifid or trifid .................................................................................................................................. Heteroscyphus deplanchei

— Underleaves not narrowed below and so widely decurrent and connate to both adjacent leaves by a band of cells usually more than six cells wide; leaf cells with minute to inconspicuous trigones; leaves evenly shaped along the same shoot, leaf apices truncate with a single short to medium tooth at both angles ............................................................................................................ Heteroscyphus coalitus (Hook.) Schiffn.

23. Leaf surfaces appearing rough because of many spinose projections ............ Lophocolea muricata (Lehm.) Nees

— Leaf surfaces smooth, rarely with cells at most bulging ............................................................................... 24

24. Plants small, shoots c. 1.5 mm wide; leaf and underleaf margins densely and sharply toothed; leaf cells less than 20 µm wide with relatively large trigones ............................................................. Lophocolea caledonica Steph.

— Plants larger, shoots usually more than 1.5 mm wide, or, if smaller, with entire or emarginate leaves; underleaf lateral margins with at most two teeth on both sides; leaf cells more than 20 µm wide with trigones small or null ................................................................................................................................................................... 25

25. Leaves fully entire with rounded apices; plants medium to large ................................................................. 26

— At least some leaves toothed or lobed or emarginate at apices, plants small to medium ............................... 27

26. Leaves widely ovate, wider or as wide as long, 0.6-0.7 mm long, dorsally assurgent-convex, giving an inflate appearance to the shoots; shoots c. 2 mm wide when flattened; underleaves 1/2 bifid, 2-2.5 times the stem width, lobes erect ...................................................................................................... Chiloscyphus trigonifolius Steph.

— Leaves ovate-oblong, 1.6-2.2 mm long, horizontally spreading, shoots somewhat complanate, 3.5-4 mm wide; underleaves more than 1/2 bifid, 4-5 times the stem width, lobes widely spreading .......................................... .......................................................................... Heteroscyphus cornutistipulus (Steph.) Thouvenot , comb. nov.

27. Leaf apices widely rounded to truncate, with 4-6 or more sharp teeth, almost equal; cell walls evenly thickened without trigones; plants medium, shoot width 1.5-2.0 mm ............................................ Heteroscyphus argutus

— Leaf apices various, teeth if any restricted to distal angles; cell walls thin, trigones minute to absent; shoot width ranging from 1 to 6 mm ............................................................................................................................. 28

28. All leaf apices bifid, lobes triangular acuminate, with piliform apices usually 3-5 cells long ............................ .................................................................................................................. Lophocolea bidentata ( L.) Dumort.

— Leaf apices various, when bilobate unevenly so in the same shoot and lobe apices not piliform .................. 29

29. Underleaves reniform, lateral margins heavily toothed-laciniate; leaf apices usually shallowly triangular with spinosely toothed angles ................................................................. Heteroscyphus caledonicus (Steph.) Schiffn.

— Underleaves reniform or not, lateral margins with 0-2 small teeth; leaf apices truncate, rounded or emarginate ................................................................................................................................................................... 30

30. Leaves rectangular, contiguous to distant, apices transversally concave, with distal angles sharply toothed or less frequently rounded, a third subapical tooth eventually present on the ventral margins; leaf cells without trigone; gynoecia and androecia on short latero-ventral leafless branches ........................................................ .................................................................................. Heteroscyphus etesseanus (Steph.) Thouvenot , comb. nov.

— Leaves ovate to oblong, more or less strongly imbricate, apices straight or varying from rounded to shallowly emarginate-bilobate often on the same shoot, angles or lobes rounded to acute; leaf cells with or without trigones; gynoecia or androecia or both on main shoots or long branches with normal vegetative leaves ............ 31

31. Leaf cells with large nodulose trigones; underleaves very wider than the stems with lobes triangular and widely divergent ...................................................................................................................... Chiloscyphus longifissus

— Leaf cells with small trigones or trigones lacking; underleaves not or hardly wider than the stems with lobes narrow, roughly parallel .............................................................................................................................. 32

32. Plants small, shoots 1-2 mm wide; leaves ovate, leaf apices conspicuously narrower that the bases, rounded to narrowly emarginate, margins crenulate by the bulging marginal cells; underleaf lobes lanceolate, rigid ...................................................................................................................... Lophocolea convexula Sande Lac.

— Plants medium sized, shoots more than 2.5 mm wide; leaves oblong, leaf apices quite as wide as the bases, from widely convex or emarginate to shortly bifid, margins smooth; underleaf lobes linear, curved ..................... 33

33. Gynoecia and androecia on short latero-ventral leafless branches; perianths cupulate, without keels, bracts strongly differentiated from normal leaves, bracteole deeply bifid; underleaf insertions concave, discs more than 2 cells long, lobes with triangular bases ................ Heteroscyphus parapilistipulus (Thouvenot) Thouvenot , comb. nov.

— Gynoecia and androecia at the end of main shoots or long leafy branches, perianths oblong and 3-angled, bracts slightly differentiated from normal leaves, bracteole oblong, toothed, not deeply bifid; underleaf insertions in an inverted U, discs very short, two cells long, lobes sublinear ............................... Lophocolea savesiana Steph.