Bazzania kokawana N.Kitag. & T.Kodama

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 : 138-139

Bazzania kokawana N.Kitag. & T.Kodama

( Figs 7H , J-L)

Journal of Japanese Botany 50 (1): 11 ( Kitagawa & Kodama 1975) — Type: Sabah ( North Borneo), Kinabalu National Park: Mamut Ridge, west of Mamut Camp; on tree trunk; s.d.; 1500-1800 m; S. Kokawa & M. Hotta 5937; holotype: OSA, not seen.

MATERIAL EXAMINED. — New Caledonia • Province sud, Dumbéa, Dumbéa valley, Sunshine branch; on dead wood in meso-hygrophilous forest; 650 m; 20.VII.1951; Hürlimann 2729a; PC [ PC0793199 ] • ibid.; on bark; 700 m; 21.VII.1951; Hürlimann 2741a; PC [ PC0793200 ] .

DISTRIBUTION IN NEW CALEDONIA. — Only known on dead wood and bark from two localities in South Province: Dumbéa ( Hürlimann 1985) and Koghis (Kitagawa 1982 in GBIF 2022).

TOTAL RANGE. — Malaysia (Sabah, Kitagawa & Kodama 1975), New Guinea, Solomon Islands ( Kitagawa 1980), New Caledonia.

DESCRIPTION

Plants

Small, prostrate, creeping among other liverworts; moist shoots 1-1.5 mm wide, stems 0.08 mm wide; terminal branching very rare, normal leaved stems usually simple with many flagelliform branches, ventral-intercalary in origin.

Leaves

Imbricate, complanate both when moist or dry, spreading at right angle, 0.40-0.55 mm long, 0.28-0.32 mm wide, sub-symmetrically elliptic-oblong, length to width ratio 1.4-1.8; every border crenulate by the protrusion of marginal cells, dorsal margins widely arched, ventral ones somewhat less convex; apices sub-entire, rounded, obtuse or retuse.

Cell

Areolation homogeneous, cuticle strongly warty to striolate; each cell including a single endogenous gemma, surrounded by a membrane closely pressed against the thin cell walls except in the corners where an empty rounded space simulates a globose trigone ( Fig. 7J ); median cells rounded to oblong, 15-25 µm wide; marginal cells similar but with the free walls strongly thickened; basal cells up to 25 µm wide, 40 µm long.

Underleaves

Erect, positioned near the leaf bases on both sides of the stem, very narrowly connate by 1-2 cells on a single side, 0.17-0.22 mm long, 0.13-0.17 mm wide, 2.0-2.5 times wider than the stem, rounded quadrate to slightly broader than long, margins entire or crenulate, lateral margins straight to convex, apices truncate,

straight to slightly convex, rounded at angles, sub-entire to shallowly bifid; cells as in the leaves (Description after New Caledonian specimens).

NOTES

Among the other members of the genus in New Caledonia, Bazzania kokawana stands out by the small size and the branching pattern, but more strikingly by its unique endogenous gemmae. The cell contents, wrapped in membranes, represent as daughter cells that can be released when leaves or underleaves are broken and likely act as propagules. Vegetative reproduction by endogenous gemmae, namely single daughter cells filling the entire lumina of mother cells in leaves and underleaves, is a very rare feature in liverworts ( Kitagawa & Kodama 1975). It occurs only in Acromastigum stellare N.Kitag. ( Kitagawa 1985)and two species of Schistochila : S. vitreocincta (Herzog) X.L. He & Glenny (2010) and S. gradsteinii Thouvenot (2021) . The three species are endemic to New Caledonia. The occurrence of such a rare feature in two distinct liverwort orders remains puzzling.

Figures

FIG. 7. — A-E, Bazzania caudistipula (Steph.) Inoue & H.A.Mill.: A, basal leaf cells;B, E, underleaves;C, median leaf cells;D, leaf;F, G, I, B. deplanchei (Gottsche ex Steph.) Jovet-Ast:F, underleaf; G, leaf; I, median leaf cells;H, J-L, B. kokawana N.Kitag & T.Kodama: H, underleaf; J, median cells of a broken leaf with daughter cells; K-L, leaves; A, C, E, from Müller NC216; B, D, from Thouvenot NC3160; F, G, I, from Thouvenot NC3430; H, J-L from Hürlimann 2741a; PC[PC0793200]. Scale bars: A, C, I, 20 µm; B, D-G, 200 µm; H, K, L, 100 µm; J, 20 µm.