Bazzania okaritana Meagher & Glenny
Bazzania okaritana Meagher & Glenny, J. Bryol. 29: 60. f. 1. 2007.
Holotype: New Zealand, South Is., Whataroa ER, Okarito, Kahuamarua Bluff, S end, 21 Sept. 1994, Glenny 9191 (CHR); isotypes: (F, MELU).
[Fig. 96: 3, 4, oil-bodies, p. 428]
Plants delicate, strongly anisophyllous, loosely creeping, pale olive-green, shoots medium, to 3.2 mm wide. Branching frequent, pseudo-dichotomous, with Frullania -type branches common and rather narrowly spreading, occasionally becoming flagelliform; branch half-leaf symmetric, narrowly ovate, undivided, tapering to an acute apex; first branch underleaf weakly to often strongly asymmetrically bilobed, with one lobe often much longer than the other, the first branch underleaf inserted close to the adjacent main shoot underleaf and at times weakly connate with it. Ventral-intercalary leafy branches sporadic; stoloniform branches occasional, long and whip-like, colorless. Leaves persistent, opposite, horizontal, widely spreading, contiguous to weakly imbricate, with moderate amount of stem exposed in dorsal aspect, widely spreading (ca. 90°); leaves nonvittate, 500–700 µm wide × 1500–1800 µm long, the insertion broad and distinctly incubous, the leaves asymmetrically rather narrowly oblong, the apex truncate to oblique, deeply 3(rarely 2)-dentate, the teeth divergent, weakly to moderately asymmetric, at times with an accessory smaller tooth on the distal sector of the ventral margin; teeth acute to subacuminate, terminating in a uniseriate row of 2–3 cells, the terminal cell tapering to a narrowly rounded to rather sharp, thick-walled summit, the leaf apex otherwise normally entire; dorsal margin moderately ampliate, moderately to rather strongly arched, at most extending to middle of stem, not or at most feebly cordate at base, the margin entire; ventral margin straight to curved gently inward, entire. Cells of leaf differentiated into a broad band comprised of enlarged cells in the median longitudinal portion of the leaf (subvittate), the subvitta occupying a large portion of leaf width; cells smaller and subquadrate near the margins; median cells subisodiametric to moderately elongated, 25–35 µm wide × 38–49 µm long, thin-walled, with trigones medium and straight-sided to weakly bulging, rather inconspicuous, the cells surrounded mostly by the thin cell walls, the trigones similarly developed or somewhat smaller near the margins and at the leaf apex; surface smooth. Oil-bodies opaque grey, with some glistening, 5–6 per median cell, 2–4 in marginal and submarginal cells of dorsal median sector of leaf, 5–9 per median basal cell, smooth and homogeneous or coarsely segmented (with to 3 segments), potato-shaped and with common pits and creases. Underleaves widely spreading, 1.6–1.9× stem width, narrowly connate with the leaves on both sides, quadrate to subquadrate, moderately narrowing to point of attachment with leaves, the apex entire-repand, at times with 4 broadly rounded feeble projections separated by markedly shallow, lunate “sinuses” (or with 3 weak rounded projections and a variably shaped but distinct lobule), at times truncate and with 4–5 slime papillae at some distance from one another (each marking the position of a repressed lobule) and without the suggestion of a sinus, the apex exceptionally with 2–3 lobuliform processes each terminating in a slime papilla; apex hyaline and decolorate in distal ca. 0.25 or a little less, with this sector comprised of subisodiametric cells, the cells in basal ca. 0.75 up to ca. 2:1 and chlorophyllose; margins of disc entire, often repand, occasionally with a tooth or lobule in distal half; cells different from those of leaves, firm-walled throughout underleaf, with trigones lacking or at most small to medium to (sporadically) weakly bulging; surface of hyaline cells finely papillose. Asexual reproduction lacking.
Androecia and gynoecia unknown.
Distribution and Ecology : Endemic to New Zealand: South Island (10–350 m). Known from two sites, the type locality in Westland EP and from Fiordland EP, in the Light River, near Lake Dale, 351 m, under Nothofagus menziesii forest on a hillslope, in a bouldery area, terrestrial with Hymenophyton leptopodum and Telaranea tuberifera (CHR 581358). At the type locality it grows on coarse gravels of compacted moraine till, on the back wall of an overhang almost facing the sea that is well protected from weather by hanging vegetation that forms a curtain at the front of the overhang. Surrounding vegetation is stunted coastal scrub.
Comments : Bazzania okaritana is most like B. exempta, but differs in the frequent development of terminal branches, the persistent leaves, underleaves that are connate on both sides, the finely papillose surface of underleaf hyaline cells, the stronger trigones of subvitta cells, and the suppressed development of lobules at the underleaf apex. Moreover, the dorsal margin of the leaf in B. okaritana is not or at most weakly cordate at the base, with the opposing leaves not closely juxtaposed vs. subcordate at the base, with the dorsal bases of opposing leaves closely juxtaposed and appearing (but not actually) connate dorsally (see Fig. 105: 2).
Terminal branches in Bazzania okaritana at times may become flagelliform and microphyllous, an unusual feature for the genus.
Underleaf lobules are present in both Bazzania okaritana and B. exempta, but are far more developed in the latter species (see Fig. 105: 5, 10–14; Fig. 106: 4). The underleaf apex in B. okaritana at times may have 4 broadly rounded feeble projections separated by markedly shallow, lunate “sinuses,” and in such cases appear rather like weaker lobule development in B. exempta. The underleaf apex may develop 3 weak, rounded projections and a variably shaped (but distinct) lobule or, exceptionally, may have 2–3 lobuliform processes of variable shape. In all cases the lobuliform as well as the low rounded processes each terminate in a slime papilla. Underleaves are often truncate, without the suggestion of a sinus, and have 4–5 slime papillae at some distance from one another, each marking the position of a repressed lobule. These are quite unlike the typical underleaves found in B. exempta.
