Lophocolea convexula Mitt.

Thouvenot, Louis, 2023, A taxonomic revision of the Lophocoleaceae Vanden Berghen (Marchantiophyta) of New Caledonia, Cryptogamie, Bryologie 20 (1), pp. 1-60 : 42-46

Lophocolea convexula Mitt.

( Figs 25 ; 26 )

Flora Vitiensis: 405 ( Mitten 1871 [1873]). — Chiloscyphus convexulus (Mitt.) J.J.Engel & R.M.Schust., Nova Hedwigia 39: 413 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. Isle of Pines, Strange s.n. (holo-, NY [ NY00965719 !]) .

Lophocolea kurzii Sande Lac., Annales Musei Botanici Lugduno-Batavi 1: 296 (1864). — Chiloscyphus kurzii (Sande Lac.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 417 ( Engel & Schuster 1984 [1985]).

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Type: Java. Tjiliwong valley , Bogor , 800’, Kurz s.n. (holo-, L [ L0060979 , fide Kitagawa in sched. 1970]!) syn. nov.

Lophocolea fragillima Steph. , Species Hepaticarum 6: 273 ( Stephani 1922). — Chiloscyphus fragillimus (Steph.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 415 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. “ Lerat ” s.n. (lecto-, here designated, G [“Lerat, Herb. Thériot”, G00112413 ]!) syn. nov.

Lophocolea parva Steph. , Species Hepaticarum 6: 287 ( Stephani 1922). — Chiloscyphus parvus (Steph.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 420 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. Franc (lecto-, here designated, G [“Nova Caledonia, 1906”, Franc s.n., “Herbier Lacouture”, G00061334 !]; isolecto-, PC [ PC0102407 !, PC0102408 !]) syn. nov.

Lophocolea papulimarginata H.A.Miller, Phytologia 47: 323 ( Miller 1981). — Lophocolea papulosa Steph. , nom. illeg. Species Hepaticarum 6: 286 ( Stephani 1922). — Chiloscyphus papulimarginatus (H.Mill.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 420 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. “ Lerat ” s.n. (lecto-, here designated, G [“ Ad arbores in summo Mt. Mou (1224 m)”, I.1906, Le Rat 44, G00112490 !]; isolecto-, REN [herb. E. G. Paris]!; syn-, G [ Pic des Sources , s.d., Le Rat 237, G00051485 !, Mt. Dzumac , IV.1907, Le Rat 225, G00051484 !, idem, Le Rat 232, G00051487 !, “ Île des Pins, Forêt de Uapan ”, V.1909, L. Le Rat 68, G00051486 !], isosyn-, REN [“ Île des Pins ”, V.1909, L. Le Rat s.n., herb. E. G. Paris]!) syn. nov.

Lophocolea pilistipula Steph. , Species Hepaticarum 6: 288 ( Stephani 1922). — Chiloscyphus pilistipulus (Steph.) J.J.Engel & R.M.Schust. , Nova Hedwigia 39: 421 ( Engel & Schuster 1984 [1985]).

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Type: New Caledonia. “ Lerat ” s.n. (lecto-, here designated, G [“ Île des Pins, forêt de Watchia, à la baie de Oupe ”, V.1909, L. Le Rat 55, G00112487 ]!; isolecto-, REN [herb. E. G. Paris]!) syn. nov.

FURTHER SPECIMENS EXAMINED. — India. Shambaganur, II.1932, Foreau 3075 as Lophocolea kurzii ( PC [ PC0167666 ]). Java. “ Ad Arengae sacchariferae truncos in agro Buitenzorgensis ”, 250 m, 18.VI.1908, Schiffner 696 as Lophocolea kurzii ( PC [ PC0763155 ]). New Caledonia. South Province, Sarraméa, on the treck from Sarraméa to the Dogny Plateau , epiphyte, c. 170 m, 5.IX.2003, F.Müller NC799 ( DR); Nouméa, Tina , border between dry forest and mangrove, 0-2 m, 24.IX.2012, Thouvenot NC2395; Farino, Grandes-Fougères Natural Park , Creek Houé , on dead wood in a mesophylous forest, 370 m, 22.IX.2016, Thouvenot NC2448; Mont Dore, Demazures forest , on dead wood in wet forest, 330-420 m, 28.IX.2016, Thouvenot NC2466; Mont Dore, Yahoué , on trunk in the mesophilous forest along the river, 122 m, 10.X.2019, Thouvenot NC2756; North Province, Pouhembout, Forêt Plate , near Ouendé Falls , 300 m, road embankment, 7.IX.2003, F.Müller NC815; South Province, Mt. Dzumac , IV.1907, Le Rat s.n. as Lophocolea papulosa ( G [ G00051484 , G00051487 ]); Pic des Sources, Le Rat s.n. “fragments” as Lophocolea papulosa ( G [ G00051485 ]); “ Île des Pins, forêt de Wapan ”, V.1909, L. Le Rat s.n. as Lophocolea papulosa ( G [ G00051486 ]); Nouméa, Ouen Toro , 28.VIII.1950, Hürlimann 2038a as Lophocolea papulosa ( PC [ PC0167657 ]); Mé Aoui , 500 m, 8.II.1951, Guillaumin & Baumann-Bodenheim 10375 as Lophocolea papulosa ( PC [ PC0167656 ], GOET); Boulari, 200 m, 23.VII. 1950, Hürlimann 2015 as Lophocolea parva ( G [ G060814 ]); Hürlimann 2017 as Lophocolea parva ( G [ G060826 ]); ex herbarium Bonati, Franc s.n. determinavit Stephani as Lophocolea fragillima ( PC [ PC0167654 ]); North Province, “ad radices Mt. Panié ”, II.1910, Le Rat s.n. “fragments” as Lophocolea autoica ( G [ G00128109 ]); South Province, Mts. Koghis , 21.IV.1914, Compton 801 as “ Lophocolea levieri ” ( BM [ BM013409501 , BM013409504 ]); Mt. Mou , on stone and mud in stream, 8.III.1914, Compton 443 as “ Lophocolea levieri ” ( BM [ BM013409502 ]).

DISTRIBUTION IN NEW CALEDONIA. — The most frequent member of Lophocoleaceae at low altitude, in both provinces of the main island, including Isle of Pines; it grows on various substrates on the ground, rarer on barks of living trees, at low to medium elevations (collected from 0 to 900 m).

TOTAL RANGE. — Java ( Söderström et al. 2010 as Lophocolea kurzii ), Fiji ( Söderström et al. 2011 as Chiloscyphus parvus ), Malaysia (Chuah-Petiot 2011 as Lophocolea kurzii ), Thailand ( Lai et al. 2008 as Lophocolea kurzii ).

DESCRIPTION

Paroecious, more rarely autoecious.

Habit

Plants small to medium, shoots 1.00-2.00 mm wide; leaves alternate, patent, dorsally assurgent, individually convex and secund, dorsally free; both terminal and lateral-intercalary branching present.

Leaves

Ovate-oblong, 0.55-1.00 mm long, 0.40-0.80 mm wide, leaf margins crenulate due to bulging marginal cells, leaf apices uneven on a same shoot, ranging from widely rounded or obtuse to retuse with widely concave sinus and rounded angles, possibly with one short acute tooth, other times leaf apices very shortly bifid with widely triangular lobes.

Cells

Hexagonal, 16-36 µm, thin-walled, trigones very small, acute, free walls bulging.

Underleaves

Small, free or very narrowly connate to one of the nearest leaves, 1-2 times the stem width, insertion in a deep sinus, apices deeply bifid, lobes narrowly lanceolate, discs shorter than wide, lateral margins with a single short to filiform tooth on both sides, more rarely similar to the lobes, then with one more tooth.

Vegetative reproduction

Gemmae lacking, but regenerants occur on perianth mouth and bract margins in some specimens.

Gametangia

Gynoecia at the apices of main shoots or long branches with normal vegetative leaves, bracts oblong, variously and shortly toothed, bracteoles bifid to the middle, lateral margins variously and shortly toothed; perianths oblong, 2-3 mm long, with cupulate-ovate base and trigone upper part, plicae narrow, acute, not winged, mouth deeply 3-fid to half the whole perianth length or more, the lobes narrowly ovate-triangular, strongly toothed to laciniate; androecia beneath the gynoecia, in series of 3-5 pairs of male bracts smaller than the female and saccate at dorsal base.

COMMENTS

In addition to the plant described by Mitten as Lophocolea convexula , this group of taxa includes other New Caledonian plants described by Stephani (1922) as distinct species but very similar in most respects and similar to the South Asian L. kurzii . They share the following common features: 1) small size and dorsally convex secund leaves; 2) ovate leaves wider at base or at small distance above, decreasing to the apices in curve lines; 3) apices variable in a same shoot, typically entire or retuse, rarely or frequently shortly bifid with wide triangular lobes; 4) leaf margins crenulate; 5) underleaves small, hardly wider than the stems, deeply bifid, usually with one small tooth on both sides; 6) usually paroecious; and 7) perianths deeply 3-fid, triangular lobes sharply toothed or laciniate. As stressed by many authors ( Sande Lacoste 1864; Schiffner 1900; Pearson 1922; Kitagawa 1973; Gradstein 2011) these plants look like Lophocolea heterophylla (Schrad.) Dumort. , a species widely distributed in the Northern Hemisphere and very rare in the tropics where it has been reported from Cuba and ranges southwards to Brazil in the Southern Hemisphere ( Gradstein & Pinheiro da Costa 2003). Besides this geographic separation, L. heterophylla may be distinguished by: 1) a leaf shape rather rectangular, not so decreasing to the apex; 2) some or many leaf apices bilobed, the lobes longer and sharper, separated by a deeper and wider sinus; 3) leaf margins entire, free cell walls flat; 4) perianths less deeply 3-fid, the lobes truncate, rounded to widely triangular, unevenly toothed; and 5) gemmae occasional and regenerants unknown. It would have been interesting to compare Brazilian material (not seen) with L. convexula . Schuster (1980) describes L. heterophylla subsp. cladogyna R.M.Schust. , a subspecies with some specific characters of L. convexula namely the rounded leaves usually entire. But the subspecies of L. heterophylla usually produce gemmae, never regenerants ( Paton 1999); in contrast, such cell clusters (regenerant) are found on leaves, bracts and perianth margins in some specimens of L. convexula collected in New Caledonia (e.g. NC2756), but gemmae have never been observed.

The holotype of Lophocolea convexula is fertile and shows paroecious sexual condition. As it is the earlier name among the many species described with this set of vegetative and sexual characters, we assume this name must be used for these plants in New Caledonia as well as in the Asian and South Pacific regions where L. kurzii was reported.

In New Caledonia, a single report of Lophocolea kurzii is from Paris (1908) based on a specimen collected by Le Rat in Loyalty Islands. This specimen is lacking in the herbarium of E. G. Paris (REN), but a lot of new species names, here considered as synonyms, were given by Stephani to the New Caledonian material sent by E. G. Paris, on the basis of different forms of characters, such as leaf and underleaf apices, cell width, leaf and perianth sizes. Careful examination shows that these characters are variable even in a same specimen. Consequently, Stephani invented new species which turned to be the same, when examined together. All the New Caledonian names, being published after the name of L. convexula , fall in synonymy with the latter, so that, the author assume that it might be more widely distributed in southern tropics.

The main differences seen in Stephani’s diagnoses and drawings or found in the type material of the New Caledonian taxa concern the perianth shapes, oblong in L. parva , cupulate in L. papulosa , cyathiform in L. convexula and obovate-conical in L. fragillima . This aspect is difficult to evaluate on some old specimens, hardly fertile or with broken organs. However, all other gynoecial characters being similar or included in a short range of continuous variation, this diversity may be resumed in a length-width ratio ranging from 4 ( L. parva ), 3-2.5 ( L. fragillima ) to 2 ( L. papulosa ). The conservation requirements of old specimens, especially if they are types, prevent to provide sufficient data on size and ornamentation of the gynoecia and to assume a continuous variability in perianth shapes. However, the observed differences seem likely the result of various stages of maturity. In vegetative features, the main changes are the underleaves and leaf orientation. Underleaves are variable in a same specimen or even in a same shoot, the lobes being sometimes shorter without filiform apex, their orientation varying from erect incurved to spreading at an angle of 30-45°. Leaf arrangements are contiguous to slightly imbricate and obliquely patent in L. fragillima , or conspicuously imbricate and patent at right angle in L. parva , less conspicuously so in further species. However, dimensions are comparable in all the types and fresh specimens measured. Thus, morphological differences are insufficient to separate New Caledonian specimens as distinct taxa.

For lectotypification purpose of Lophocolea pilistipula , the specimen G00112487 from Pines Island is selected here since it perfectly matches the original description and belongs to the original materiel examined by Stephani as shown by the handwritten name and mentions “ n.sp.” and “ c. per. ”. The original description includes perianth characters and the selected lectotype is the single fertile specimen among the three type specimens kept at G. The remaining material at G, from Dogny, is sterile and larger in all the dimensions. They belong to another species described as Heteroscyphus parapilistipulus (see above). The original materials of L. fragillima and L. parva at G each comprise a single packet handwritten “ n.sp. ” by Stephani and are the only ones available for lectotypification. Among five packets of L. papulosa available, the lectotype selected have the label marked “ original ”, and “ autoica , c. per.” handwritten by Stephani. This is also the type designated by Miller (1981) when he replaced its epithet by papulimarginata .

Figures

FIG. 25. — Lophocolea convexula Mitt.: A, shoot portion, dorsal view; B, C, K, L, leaves; D, median cells; E, G, N-P, underleaves; F, leaf lobe; H, marginal cells; I, J, shoot portions, ventral view; M, perianth with a bract; Q, leaf apex, strongly crenulate margin; R, female bract; S, female bracteole. A-H, drawn from the holotype of Lophocolea kurzii Sande Lac. (L0060979); I-L, N-S, from the lectotype of Lophocolea fragillima Steph. (G00112413); M, from the lectotype of Lophocolea papulimarginata H.A.Miller (G00112490). Scale bars: A, I, J, M, R, S, 1 mm; B, C, E, G, K, L, N-P, 200 µm; D, F, H, 50 µm; Q, 100 µm.

FIG. 26. — Lophocolea convexula Mitt.: A, G, P, shoot portion, ventral view; B, leaf and underleaf; C-E, J, S-U, leaf apices; F, H, I, N, O, R, V, underleaves; K, marginal cells; L, autoicous gametangia: perianth terminal with one pair of female bracts and four pairs of male bracts below, dorsal view; M, Q, leaves; W, adjacent leaves on stem; X, apex margin; Y, median cells. A-F, drawn from the lectotype of Lophocolea pilistipula Steph. (G00112487); G-K, from the lectotype of L. papulimarginata H.A.Miller (G00112490); M-U, from the lectotype of Lophocolea parva Steph. (G00061334); L, V-Y, from the isotype of Lophocolea parva (PC0102408). Scale bars: A, G, L, P, W, 1 mm; B, H, I, M-O, Q, R, 200 µm; C-F, J, S-V, 100 µm; K, X, Y, 50 µm.