Bazzania consociata H. A. Mill.
Creators: name: Thouvenot, Louis
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Marchantiophyta
Jungermanniopsida
Jungermanniales
Lepidoziaceae
Bazzania
Bazzania consociata

description: Bazzania consociata (Steph.) H.A.Mill.
(Figs 1A, C; 8)
Phytologia 47: 320 (Miller 1981). — Mastigobryum consociatum Steph., Species hepaticarum 6: 458 (Stephani 1924).
— Type: New Caledonia, Franc s.n. (lecto-, designated here fide Kitagawa (s.d., in sched.), G [Tao, 600 m, s.d., Franc s.n. G00066871]! lecto-, G [“forêt de Tao, de 100 à 600 m ”, I.1910, Franc s.n. G00066872]!; PC [PC0101765]!).
Mastigobryum leratii Beauverd, Species hepaticarum 6: 477 (Stephani 1924). — Bazzania leratii (Beauverd) H.A.Mill. Phytologia 47: 320 (Miller 1981). — Type: New Caledonia, Mastigobryum pulchellum Steph. mss, non M. pulchellum Steph. 1908., Le Rat. (lecto-, designated here, G[“ Nov. Caled. Septentr. In fossis inter Panié et Hyenghene’’, II.1910, Le Rat 310. ex herbarium Général Paris, G00067047]!; para-, REN[REN000232]!) syn. nov.
MATERIAL EXAMINED. — New Caledonia • North Province, Diahot; on sand in a rock cleft in the Diahot riverbed; c. 430 m; 31.VIII.1951; Hürlimann 2904; PC [PC0793192], G [G00240716] • ibid.; on riverbank of a Diahot tributary; c. 450 m; 30.VIII.1951; Hürlimann 2895; PC [PC0793191] • South Province, Sarraméa, Dogny; VII.1909; Le Rat 313 (herbarium E.G. Paris as Mastigobryum dognyanum Steph. ex Paris; REN [REN000218] • Dogny plateau; on rocks in a creek bed in wet forest, volcano-sedimentary bedrock; 1000 m; 15.IV.2013; Coulerie COU074, COU075 • Dumbéa, Mt Bouo; on dead tree in a wet forest in ultramafic massif; 930 m; 16.IX.2016; Thouvenot NC3686.
DISTRIBUTION IN NEW CALEDONIA. — Rare in both provinces of Grande Terre.
TOTAL RANGE. — Endemic to New Caledonia.
DESCRIPTION
Plants
Small, fragile, soft, moist shoots 1.0- 1.5 mm wide, stems 0.16-0.30 mm thick, terminal branching common, pseudo-dichotomous, ventral-intercalary branches flagelliform.
Leaves
Imbricate, when moist sub-complanate, slightly convex, widely spreading, deflexed when dry; leaves asymmetrically ovate-oblong, hardly falcate, 0.80-1.00 mm long, 0.50-0.60 mm wide near bases, 0.24-0.30 mm at apices, length-width ratio 1.5-2.0; cuticle smooth; margins 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 convex at bases; apices obliquely truncate, shallowly 3-lobulate-dentate, lobules short, widely triangular or tooth like, 1-4 cells long, apical margins with scattered sharp denticulations; leaves usually with a subvitta of 6(-9) rows of large cells contrasting with the surrounding smaller cells occupying a wide dorsal intramarginal zone and a narrow ventral band.
Cells
Rather homogeneous, sub-quadrate to sub-rectangular, 14-22(-25) µm as wide as long, cell walls firm to medium thickened, trigones lacking or small and inconspicuous, marginal cells slightly smaller, inner basal cells oblong to long rectangular, 25-28(-35) µm wide, 35-50(-75) µm long, thin-walled with large acute trigones not confluent.
Underleaves
Erect-patent recurved, transversally inserted, positioned near and widely connate to the leaf bases on both sides of the stem, reniform to sub-rectangular and transversally elongate, 0.30- 0.45 mm long, 0.35-0.60 mm wide, 2-3 times wider than the stem; lateral margins with some shallow bumps, apices truncate with rounded angles, lobulate-dentate; internal cells rectangular with evenly thickened walls without trigones; in some or many underleaves, a hyaline border usually occurs but the hyaline cells are slightly differentiated from the chlorophyllous cells, the walls being a little thinner (Description after the isotype [PC0101765]).
NOTES
Bazzania consociata is close to B. bescherellei with which it shares: 1) asymmetrically ovate-oblong leaves; 2) leaf apices shortly 3-dentate in typical forms; and 3) underleaves relatively widely connate to the leaves on both sides, without appendages, 2-3 × wider than the stem. See comments under the latter. However, typical B. consociata can be distinguished by its smaller size (shoots 1.0- 1.5 mm wide versus 2.4-2.5 mm wide in B. bescherellei), wide hyaline underleaf margins, although their width varies, an obvious subvitta in most of the leaves, the median cell walls evenly thick with or without inconspicuous trigones, the incised-dentate underleaf apices.
Both Mastigobryum leratii and M. consociatum were described by Stephani in the last volume of Species hepaticarum (Stephani 1924) but their diagnoses are very similar. The former differs from the latter only in the smaller underleaf sizes and the lack of mention of marginal leaf denticulations. After checking the types of both species at G and REN, I did not find any discriminating characters with specific values, since the characters given by Stephani as specific of M. leratii also occur in many specimens of B. consociata. In view of this, I understand why no specimens have been identified as Bazzania leratii since the type collection. Notably by Hürlimann (1985), who cites several B. consociata specimens.
Stephani (1924) described Macromitrium leratii after a specimen initially assigned to M. pulchellum, a name used before for a species from Samoa (Stephani 1908b). The New Caledonian specimen here designated as a lectotype was kept at G in the folder holding the type of M. pulchellum from Samoa. It was annotated by Grolle in 1977 (in sched.) that the New Caledonian specimen was not M. pulchellum. The isolectotype, in the E.G. Paris herbarium (REN), is kept in an original envelope bearing the same name and collecting data as the lectotype.
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 page 132, DOI: 10.5252/cryptogamie-bryologie2024v45a6, http://zenodo.org/record/14546400