Heteroscyphus argutus (Reinw., Blume & Nees) Schiffn.

Thouvenot, Louis, 2023, A taxonomic revision of the Lophocoleaceae Vanden Berghen (Marchantiophyta) of New Caledonia, Cryptogamie, Bryologie 20 (1), pp. 1-60 : 10-12

Heteroscyphus argutus (Reinw., Blume & Nees) Schiffn.

( Fig. 4 )

Oesterreichische Botanische Zeitschrift 60: 172 ( Schiffner 1910). — Jungermannia arguta Reinw., Blume & Nees , Nova Acta Physicomedica Academiae Caesareae Leopoldino-Carolinae Naturae Curiosorum Exhibentia Ephemerides sive Observationes Historias et Experimenta 12: 206 ( Reinwardt et al. 1824). — Chiloscyphus argutus (Reinw., Blume & Nees) Nees , Synopsis Hepaticarum: 183 ( Gottsche et al. 1845).

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Type: Java. “In montibus Sadjra […] Iavae insulae, prope Rawayan…”, Blume s.n. (G[G00280112]).

Chiloscyphus acutus Steph. , Species Hepaticarum 6: 302 ( Stephani 1922). — Type: New Caledonia. “ Lerat ” s.n. (lecto-, here designated, G [“ Île des Pins , Forêt de Condo ”, V.1909, L. Le Rat 44, G00069505 ]!; isolecto-, REN [herb. E. G. Paris]!; syn-, G[“ Île des Pins , Grotte d’Aoupéna ”, V.1909, L. Le Rat 72, G00282946 ]!) syn. nov.

FURTHER SPECIMENS EXAMINED. — New Caledonia. South Province, Farino, Grandes Fougères Nature Park , Houé river , 430 m, 24.IX.2008, Thouvenot NC435; 370 m, 16.IX.2016, Thouvenot NC2450; La Foa, Mts. Koghis , 500 m, IV.2013, Coulerie COU143; Mt. Dogny , 540 m, 9.V.2015, Metoyer MET061; Mt. Dzumac , IV.1907, Le Rat s.n. as “ Chiloscyphus jackii ” ( REN [herb. E. G. Paris]); Mts. Koghis , on bark and rocks near stream, 1000 ft, forest, 21.IV.1914, Compton 801 as Chiloscyphus argutus ( BM [ BM013409505 ]).

DISTRIBUTION IN NEW CALEDONIA. — Frequent in North and South Provinces, including Isle of Pines, in moist conditions on ground, dead wood, trees or tree ferns, collected between 300-1200 m.

TOTAL RANGE. — Southern Asia, Indonesia, Oceania, Australasia, Africa.

DESCRIPTION

Based on the lectotype of Chiloscyphus acutus . Further descriptions and illustrations in Piippo (1985).

Dioecious.

Habit

Plants medium, wet shoots 1.50-2.50 mm wide; leaves alternate to subopposite, dorsally obliquely assurgent in a wide angle c. 130°, spreading at a right angle when flattened.

Leaves

Ovate-oblong, 1.20-1.40 mm long, 1.00- 1.20 mm wide at bases, 0.60-0.80 mm below apices, apices widely rounded, with usually four linear teeth, up to eight uniseriate cells long, the upper ones acute to narrowly rounded, sometimes with one or two additional teeth, lateral margins naked but usually with one subapical tooth on both dorsal and ventral sides and the ventral often with a tooth more.

Cells

Leaf cells hexagonal, their size progressively increasing up to down, (20-)25-35 µm wide, cell walls evenly a little thick, without trigones.

Underleaves

Free on both sides or unilaterally narrowly connate to the nearest leaf, overall dimensions 0.40-0.50 mm long, 0.80- 1.00 mm wide, disc transversally elongate, narrow, 0.10- 0.15 mm wide, 0.40 mm long, sinus wide, flat or shallowly convex, bifid with lobes widely spreading, curved frontward, horn like, narrowly triangular at base, evenly acuminate, ending in linear points, lateral margins short, each one with a linear segment backward turned.

Gametangia

At the end of very abbreviated leafless branches; gynoecia with bracts and bracteoles unevenly toothed, perianths cyathiform, deeply 3-lobate, lobes spinose-toothed; androecia in long narrow spikes made of 3-9 pairs of bracts, bracts deeply bifid with narrow segments ending in 4-6 uniseriate cells.

COMMENTS

Based on Stephani’s diagnoses and drawings, Chiloscyphus acutus is separated from C. argutus by the leaf apices, which are acute instead of truncate. In the type specimens, however, the leaf apices are truncate to convex, rarely acute, with 4-6 short teeth like Heteroscyphus argutus . All other features are identical.

Both specimens of Chiloscyphus acutus in G were collected by Mrs Louise Le Rat on Île des Pins and sent by E. G. Paris to Stephani for identification. One of them, collected in Condo Forest, was annotated “ n.sp. ”, “ original ” and “ cum flore sterili ” by Stephani, and can therefore be selected as the lectotype. The second, collected in Aoupéna cove, was first identified by Paris as Plagiochila ; Stephani subsequently added the name Chiloscyphus acutus . As it was collected in a nearby locality at the same date by the same collector, it may reasonably be regarded as a syntype of C. acutus .

Figures

FIG. 4. — Heteroscyphus argutus (Reinw., Blume & Nees) Schiffn.: A, portion of shoot in ventral view; B, leaf apices; C, cells; D, underleaf. All drawn from the lectotype of Chiloscyphus acutus Steph. (G00069505). Scale bars: A, B, 500 µm; C, 20 µm; D, 200 µm.