Bazzania bescherellei Steph.

Thouvenot, Louis, 2024, A revision of the genus Bazzania Gray (Lepidoziaceae, Marchantiophyta) in New Caledonia with a review of the type specimens, Cryptogamie, Bryologie 20 (6), pp. 117-154 : 128-130

Bazzania bescherellei Steph.

( Figs 1B ; 6 )

Hedwigia 32 (4): 204 ( Stephani 1893). — Mastigobryum bescherellei (Steph.) Steph. , Bulletin de l’Herbier Boissier, série 2, 8 (10): 766 ( Stephani 1908b). — Type: New Caledonia, herb. Bescherelle (lecto-, designated here fide Kitagawa (1970, in sched.), G[“Nova Caledonia”, Anon. s.n., ex herb. Bescherelle, G00066912]!; paralecto-, G[G00066913]!).

MATERIAL EXAMINED. — New Caledonia • North Province, Hienghène, Panié massif, between Bwa Téan and Payolé ; 1000 m; 09.X.2009; Thouvenot NC 3337 • South Province, Païta, Mt Mou ; 1190 m; on bark of branch in cloud forest, ultramafic massif; 17.IX.2016; Thouvenot NC 3593 • Mt Mou summit; 1000 m; VI.1909; Le Rat s.n.; REN [ REN000217 ] • Pic des Mousses ( Mt Mou ); 1200 m; 23.VIII.1950; Baumann-Bodenheim 5741; PC [ PC0793142 ] • Mt Humboldt ; on bark in mountain scrubland, ultramafic massif; 1400 m; 01.X.2008; Thouvenot NC 3679 • ibid.; 1205 m; 30.IX.2008; Thouvenot NC 3676 • Dumbéa; Mt To ; 880 m; 10. V.1951; Hürlimann 2569b; PC [ PC0793143 ], Hürlimann 2579 p.p.; PC [ PC0793205 ] • Montagne des Sources ; on bark in wet forest with Araucaria rulei F.Muell. ; 940 m; 21.IX.2016; Thouvenot NC 3680 • Sarraméa, Mé Amméri ; on bark in forest; c. 700 m; 29.XI.1950; Guillaumin & Baumann-Bodenheim 8905; PC [ PC0793141 ] • Mont Dore, Mouirange ; on rocks in ultramafic massif; 500- 550 m; 17.IX.2019; Thouvenot NC 3296 • Yaté, near the Goro old mine; on rocks in wooded scrubland, ultramafic massif; 242 m; 31.III.2016; Métoyer 110 • Pic du Grand Kaori ; on rocks in xerophilous forest; 250 m; 22.X.2012; Thouvenot NC 731 • Creek Nooti ; on bark at ground level in creek bed, ultramafic massif; 426 m; 05.X.2019; Thouvenot NC 2737 .

DISTRIBUTION IN NEW CALEDONIA. — Frequent on trunks and branches in both provinces of Grande Terre at any elevation.

TOTAL RANGE. — Endemic to New Caledonia.

DESCRIPTION

Plants

Medium sized, rigid; moist shoots 2.4-2.5 mm wide, stems 0.30-0.35 mm thick, terminal branching common, pseudo-dichotomous, ventral-intercalary branches numerous, flagelliform.

Leaves

Imbricate, complanate when moist, a little convex, obliquely spreading at a wide angle, more than 60°, deflexed when dry; leaves asymmetrically ovate-oblong, (0.70-)1.3(-1.50) mm long, (0.40-) 0.85 mm wide near the bases, (0.28-) 0.50 mm at apices, length-width ratio (1.5-)1.6(-1.9); leaf surface smooth; margins entire, or unevenly denticulate-crenulate in upper parts, dorsal margins widely arched at bases, sub-straight to slightly convex above, ventral margins sub-straight to hardly concave, shortly rounded at bases; apices obliquely truncate to obtuse, from sub-entire to shortly dissected, typically three dentate with the outer teeth narrowly triangular, acute, 1-3 cells long, and the median tooth widely triangular to flat, with few denticulations or none.

Cells

Heterogeneous, gradually increasing in length and trigone size towards the centre-basal part of the leaves, drawing a more or less obvious subvitta; median cells rounded quadrate to oblong, 12-20 µm wide, 12-35 µm long, medium thick-walled, trigones acute, large, but often hardly larger than the cell walls, marginal cells smaller, otherwise like the median cells, cells in the subvitta oblong to long rectangular, 18-24(-38) µm wide, 35-45(-68) µm long, with medium to thick walls and large trigones, sometimes confluent.

Underleaves

Obliquely inserted, positioned near and widely connate to the leaf bases on both sides of the stem, erect-patent, recurved,

slightly wider than long, with rounded corners, (0.30-) 0.50- 0.60 mm long, (0.45-) 0.60-0.75 mm wide, 2 (-3) times wider than the stem; apices truncate, sub-straight or with some shallow rounded lobules, usually entire margined but sometimes with some sharp teeth; internal cells oblong to narrowly rectangular with thick walls and large trigones; in some or many underleaves, an uneven marginal band of 0-2 files of hyaline cells, with medium thick walls lacking trigones, may be present without forming a true hyaline band (Description after the lectotype).

NOTES

Bazzania bescherellei is close to B. consociata and the two species could be confused if the hyaline borders of the underleaves of B. consociata are overlooked. Both are small plants with the leaves ovate-oblong, shortly 3-dentate. In the type specimens, leaves and underleaves may be variable along shoot segments of a same plant. In typical forms, areolation pat - terns are distinctive, since B. bescherellei has median cells with neat trigones, becoming progressively larger toward the base, whereas median cells of B. consociata have less conspicuous trigones and are sharply separated from the larger oblong cells with large trigones forming a clear subvitta. Further characters may be useful to separate the two species such as the plant size, B. bescherellei being usually larger (0.70-)1.3(-1.50) mm long versus 0.80-1.00 mm long.

Even though there is no doubt that Bazzania bescherellei is the basionym rather than Mastigobryum bescherellei , Stephani’s name is puzzling since, at the same time, he used Mastigobryum and rejected expressly Bazzania in his correspondence with Bescherelle (1887-1893, manuscript kept in the MNHN Library, Botany (MS CRY 170/150-154)), while he inconsistently used the name Bazzania for 21 species in his Hepaticarum species novae ( Stephani 1893). The combination Bazzania bescherellei (Steph.) Tixier (1985) is superfluous.

Figures

FIG. 1. — Leaves and underleaves drawn at the same scale from type specimens of New Caledonian Bazzania Gray species: A, Mastigobryum leratii Beauverd ex Steph.; A1, underleaf; A2, leaf (both from isotype REN000232); A3, leaf (lectotype G00067047); B, M. bescherellei (Steph.) Steph. (lectotype G00066912); B1, B4, underleaves;B2, B3, leaves;C, M.consociatum Steph.(syntype PC0101765); C1, C2, underleaves;C3, leaf;D, M.francanumSteph.(lectotype G00066893); D1, D2, D5, leaves; D3, D4, underleaves; E, M. dognyense Steph. (lectotype G0011718); E1, leaf; E2, E3, underleaves; F, M. incrassatum Steph. (isolectotype PC0101851); F1, F2, underleaves; F3, F4, leaves; G, M. marginatum Steph. (lectotype G00066911); G1, leaf; G2, underleaf; H, M. paucidens Steph. (holotype G00066787); H1, leaf; H2, underleaf; I, M. quadratum Steph. (lectotype G00066891); I1, leaf; I2, I3, underleaves. Scale bar: 200 µm.

FIG. 6. — Bazzania bescherellei Steph.: A-D, leaves; E, G-J, underleaves; F, leaf base; K, basal leaf cells; L, median leaf cells. A, E, H, from Hürlimann 2569b; PC[PC0793143]; B, C, J-L, from Thouvenot NC731; D, from Thouvenot NC3676; F, G, from Thouvenot NC3296; I, from Hürlimann 2579; PC[PC0793205]. Scale bars: A-E, 200 µm; F-J, 100 µm; K, L, 20 µm.