Bazzania nova J.J.Engel & G.L.Merr.
Bazzania nova J.J.Engel & Merrill, Bryologist 97: 313. f. 1. 1994.
Holotype: New Zealand, South Is., Westland Prov., Waikukupa River, S of Waiho River, ca. 500 ft., Child H4926 (F); isotype: (CHR).
[Fig. 99; Fig. 100: 3, oil-bodies, p. 441]
Plants strongly anisophyllous, prostrate, light green; shoots small, to 2.6 mm wide. Branching pseudo-dichotomous, of Frullania type, widely spreading; branch half-leaf ± symmetric, narrowly ovate, undivided, tapering to a sharp apex; first branch underleaf (2)3-lobed, with accessory teeth on margin of disc, free, obliquely inserted on ventral-lateral side of main axis somewhat below base of branch. Ventral-intercalary leafy branches rarely produced; stoloniform branches sporadically produced. Stems ± slender, the cortical cells moderately thick-walled. Leaves caducous, subopposite, horizontal, loosely imbricate, with much of stem exposed in dorsal aspect, widely spreading (ca. 90°); leaves not vittate, 400–560(615) µm wide × 685–880(945) µm long, distinctly incubous, asymmetrically ovate-ligulate, straight or subfalcate; apex moderately to strongly oblique, asymmetrically 3-dentate, the ventral tooth often strongly ventrally displaced, the teeth 2–4(6) cells wide at base, narrowly to broadly acute, at times apiculate, terminating in a single cell or a uniseriate row of 2–3 cells, the terminal cell tapering to a rounded, thick-walled point, the leaf apex otherwise entire; dorsal margin ampliate, distinctly arched but usually not extending to middle of stem, cordate at base, the margin entire; ventral margin straight, entire or sparingly and irregularly denticulate. Cells of leaf differentiated into a broad band of enlarged rectangular cells in the median longitudinal portion of the leaf (subvittate), the subvitta occupying most of leaf width in smaller leaves; cells smaller and subquadrate near the margins; median cells 24–34 µm wide × 26–38(48) µm long, thin-walled, trigones ± knot-like in all leaf cells, the free wall also strongly thickened; surface smooth or the teeth finely papillose. Oil-bodies in subvitta (3)4–6(10) per cell, colorless, homogeneous and smooth or coarsely granular on surface due to surface restrictions, crescentic with parallel sides and rounded ends, less often ellipsoidal, 7–10 × 9–24 µm; at midleaf near margin, 2–3 per cell, smooth or coarsely lumpy, 6 × 8–16 µm; intramarginal row of cells with only (1)2 oil-bodies per cell. Underleaves firm, erect to widely spreading, connate on both sides, quadrate to cuneate to subrectangular, broader than long, the apex ± regularly to irregularly 4–6-lobed to ca. 0.3, the lobes rigid, somewhat divergent, often reflexed, slenderly acuminate to spiniform, at times truncate, entire or variously armed with a divergent spur, the lobe then appearing bent, truncate, hook-like, or twisted, the lobes ultimately terminating in a uniseriate row of 2–4 cells, the terminal cell tapering to a thick-walled point; margins of disc with a single tooth, or the accessory teeth lobuliform, the underleaf then appearing 6–8-lobed; no hyaline cells present; cells with trigones as in leaves; surface minutely papillose on tips of lobes.
Asexual reproduction by caducous leaves and regeneration from leaves.
Androecia and gynoecia not seen.
Distribution and Ecology : Endemic to New Zealand: South Island (35–1200 m), North Island (1310 m). Known from Westland (Waikukupa River, Haupiri River, Reefton), Western Nelson (Little Wanganui River, Lead Hills) and Gisborne (Maungawaru Plateau) EPs. Probably more widespread and common than records indicate.
In forests, often along ridgelines, of Nothofagus truncata, Weinmannia racemosa, Quintinia serrata, Metrosideros umbellata and Libocedrus bidwillii. Epiphytic (recorded on trunks of N. truncata, Griselinia littoralis) with Hymenophyllum flabellatum, Plagiochila annotina and Rhizogonium pennatum or on humic soil in damp protected places with Leucobryum candidum, Rhizogonium distichum, R. pennatum and Zoopsidella caledonica. Also found on a stump of Halocarpus biformis with Hymenophyllum malingii.
At Paparoa Natl. Park (Inland Pack Track, ca. 35 m), on bark of Nothofagus in an area of limestone outcrops and cliffs in a mixed broadleaf forest with Nothofagus and Leptospermum scoparium. Also on the Maungawaru Plateau (Raukumara Ra., 1310 m) with Bazzania monilinervis and Leucobryum candidum (leg. Druce, MPN sub B. monilinervis).
Comments : The most striking feature of this species is the unique form and texture of the underleaves, which are ± regularly divided into 4–6 slenderly acuminate, rigid lobes (Fig. 99: 7) and are composed entirely of thick-walled cells, with well-developed trigones (Fig. 99: 8). The other nonvittate, opposite-leaved Bazzania species in New Zealand have undivided underleaves, with a variously developed hyaline sector composed of leptodermous cells. Bazzania nidita and B. tayloriana have regularly lobed underleaves that are composed of decolorate cells, entirely or in major part, and have alternate, vittate leaves.
The underleaf lobes of Bazzania nova often appear twisted, with the spur-like, lateral projections projecting abaxially, reminiscent of the projecting spines on the underleaf lobes of Lepidozia setigera.
Most likely to be confused with Bazzania hochstetteri because the leaves of both species are caducous and both are usually epiphytic. The underleaves of B. nova differ from those of B. hochstetteri in lacking any hyaline cells and in having conspicuously long marginal lobes.
