Bazzania incrassata N. Kitag.
Creators: name: Thouvenot, Louis
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Jungermanniales
Lepidoziaceae
Bazzania
Bazzania incrassata

description: Bazzania incrassata (Steph.) N.Kitag.
(Figs 1F; 10)
Journal of the Hattori Botanical Laboratory 36: 448 (Kitagawa 1972[1973]). — Mastigobryum incrassatum Steph., Species Hepaticarum 6: 469 (Stephani 1924).
— Type: New Caledonia, Franc s.n. (lecto-, designated here fide Kitagawa (1970, in sched.), G [Tao forest, 600-800 m, I.1910, Franc s.n. G00066894]!; paralecto-, PC [PC0101851]!; para-, G [G00066895, G00066896]!). Mastigobryum varians Steph., Species Hepaticarum 6: 484 (Stephani 1924).
— Type: New Caledonia, Le Rat s.n. (lecto-, designated here, G [Pic des Sources; VI.1909; Le Rat s.n. G00120752]! isolecto-, REN [REN000230, REN000231]!; para-, G [Pic des Sources, s.d., Le Rat s.n. G00120753]!; PC [Pic des Sources; IX.1909; Le Rat s.n. PC0101823]).
MATERIAL EXAMINED. — New Caledonia • South Province, Dumbéa, Montagne des Sources; on bark in ridge wet forest with Araucaria rulei F.Muell., mixed with Bazzania deplanchei and Kurzia caduciloba R.M.Schust., in ultramafic massif; 950 m; 21.IX.2016; Thouvenot NC3449 • Montagne des Sources tack; on dead wood in mesophilous forest with Nothofagus balansae (Baill.) Steenis; 490 m; 28.XII.1950; Hürlimann 2211; PC [PC0793195] • Mt Bouo; on bark in wet forest, ultramafic massif; 930 m; 16.IX.2016; Thouvenot NC3473 • Yaté, Rivière Bleue natural park, la Tranchée; on bark of thin tree, lowland wet forest, ultramafic massif; 222 m; 16.X.2016; Thouvenot NC3471 • Rivière Blanche, Bon Secours; on bark in mesophilous forest; 400 m; 31.III.1951; Guillemin & Baumann 11911; PC [PC0793193] • Creek Nooti; on dead wood and ground, wet forest, ultramafic massif; 442 m; 5.X.2019; Thouvenot NC3055 • Wé Toa; on stump in wet forest, ultramafic massif; 478 m; 8.IX.2019; Thouvenot NC2975 • La Foa, Dogny plateau; on litter in wet forest; 910 m; 23.IX.2008; Thouvenot NC633 • Thio, Grand Borindi; on bark in dry forest, ultramafic massif; 193 m; 22.X.2016; Thouvenot NC3474.
DISTRIBUTION IN NEW CALEDONIA. — The type locality is Tao in North Province, but recent collections of typical forms were only found in South Province (Hürlimann 1985 and this paper), mainly in ultramafic massifs. Conversely, depauperate forms were collected in sedimentary massifs of the central range or remote mountains in both provinces, that raises the issue of links between morphology and ecological conditions.
TOTAL RANGE. — Endemic to New Caledonia.
DESCRIPTION
Plants variable.
Typical plants
Medium, decumbent, often creeping in dense wefts among other Lepidoziaceae; moist shoots 2-2.5 mm wide, stems 0.28-0.30 mm wide; terminal branching common, pseudo-dichotomous, ventral-intercalary branches usually flagelliform, rarely normal leaved.
Leaves
Imbricate, widely spreading at 60-90°, complanate both in moist or dry condition,more rarely deflexed when dry, slightly convex, ovate-oblongtoovate-ligulate,falcate,asymmetrical,1.00- 1.40 mm long, 0.45-0.62mm wide near bases, 0.30-0.40 mm below apices, length-width ratio 2.0-2.5; cuticle warty, at least in borders and apical lobes,both lateral margins entire to crenulate,bases of dorsal margins strongly arched up to 1/2-2/3 the length, straight above, ventral margins concave to sub-straight;apices obliquely truncate, typically deeply trifid, lobes narrowly triangular, acute, 5(-8) cells long, 2(-4) cells wide at bases, lateral ones usually divergent, the central erect, unevenly shorter, wider or lacking.
Cell
Walls contrasting with lumina: lumina opaque to dark; trigones large and translucent, areolation heterogeneous with a wide subvitta, more or less sharply delimited, made of 5(-7) files of longer and wider cells, ending at short distance below apices, median cells in dorsal sectors rounded-oblong,20-35 µm wide, 25-35 µm long, thin or thick-walled, with large bulging trigones, cellular contents dark with small to medium persistent oil bodies; marginal cells smaller with free walls thicker and warty, cells oblate in postical margins; inner cells oblong to rectangular, 35-40 µm wide, 60-70 µm long, thin-walled with huge trigones usually confluent, cell lumina filled by very large persistent oil bodies.
Underleaves
Spreading-recurved,obliquely inserted,positioned close to the leaf bases on both sides of the stem and narrowly connate on one or both sides, sub-quadrate to longer than wide in overall shape, 0.50-0.70 mm long, 0.40-0.70mm wide,1.5-2 times wider than the stem; lateral margins entire, convex or with a widely arched lobe, narrowing beneath the lobed apices, apices deeply dissected, typically 3-lobed, lobes similar to the leaf lobes, the lateral often divergent and somewhat horn-like, the central often lacking or shorter, additional lobes may occur; underleaf cells like in the leaves, the central basal cells may be narrower and thicker walled.
Weak forms
Differ in being smaller, shoots 1.5-2.0 mm wide; leaves 0.55- 0.80 mm long, 0.45-0.50 mm wide, ovate-oblong, margins evenly crenulate, apices entire to shallowly angled or shortly dentate; median leaf cells with smaller trigones, otherwise like the cells in the typical forms; underleaves with typical shape but smaller, 1.5 times wider than the stem, 0.23-0.30 mm long, 0.30-0.35 mm wide.
NOTES
Bazzania incrassata is a very variable species,but always noteworthy by a contrasting areolation: translucent large trigones and opaque to dark cell lumina make up the whole cell patchwork like a leopard skin. This typical tissue is obvious in the upper branches, and in the most robust populations while leaves in the lower sections have median cells with smaller or inconspicuous trigones.Furthermore,typical forms have:1) leaves and underleaves distinctive in shape, both with apices deeply 3-lobed; 2) leaves ovate-oblong to lingulate, sparingly to strongly falcate, the leaf lobes typically narrowly triangular to finger-like, often divergent; and 3) underleaves subquadrate, spreading-recurved to nearly squarrose,the typical underleaf lobes widely triangular.However, in some populations, lobes are lacking or strongly reduced in most of the leaves and underleaves, then the apices seem entire, angulate to shortly dentate. But many specimens have at least a few leaves and underleaves with the typical ornamentation.
Kitagawa examined and annotated as types the two parts of the original material of Mastigobryum varians kept at G (1970, in sched.), but he did not select a lectotype from them. The lectotype and isotypes of M. varians at G, PC and REN showed no significant differences from the type of M. incrassata except for the more denticulate leaf margin and somewhat less deeply incised leaf apices. I agree with Kitagawa’s treatment of M. varians as a synonym of Bazzania incrassata.
Bazzania subtilis (Sande Lac.) Trevis. differs from Bazzania incrassata mainly by the underleaf orientation and insertion, patent instead of squarrose, and positioned close to the leaf bases on a single side of the stem. In addition, it can be distinguished by: 1) smaller size; 2) smaller leaf lobes, not divergent; 3) relatively wider leaves, hardly falcate or not; and 4) underleaves with more lobes, narrower and erect. The relationship between these two species and their weak forms needs further investigation.
description: Published as part of Thouvenot, Louis, 2024, A revision of the genus Bazzania Gray (Lepidoziaceae, Marchantiophyta) in New Caledonia with a review of the type specimens, pp. 117-154 in Cryptogamie, Bryologie 20 (6) on pages 136-138, DOI: 10.5252/cryptogamie-bryologie2024v45a6, http://zenodo.org/record/14546400