Bazzania involuta (Mont.) Trevis.
Herpetium involutum Mont., Ann. Sci. Nat. II. 19: 253. 1843. Jungermannia involuta (Mont.) Hook.f. & Taylor in Hook.f., Bot. Antarc. Voy. 1: 159. 1845. Mastigobryum involutum (Mont.) Lindenb. in Gottsche, Lindenb. & Nees, Syn. Hepat. 220. 1845. Bazzania involuta (Mont.) Trevis., Mem. Reale Ist. Lombardo Sci. Lett. III, 4: 414. 1877.
Type: Auckland Is., Hombron.
Type: Auckland Is., “(Hooker jun. in Hb. Gottsche).”
Mastigobryum elegans Colenso, Trans. & Proc. New Zealand Inst. 19: 288. 1887 (1886).
Bazzania involuta fo. elegans (Colenso) Rodway, Tasman. Bryophy. 2: 74. 1916.
Type: New Zealand, Waipawa Co., Mangatawhainui River, near Norsewood, 1881–86, Colenso 1398 (G!).
[Plate 8B; Fig. 93; Fig. 96: 1, 2, oil-bodies, p. 428]
Plants subisophyllous, large, ascending to stiffly erect in loose or rather dense cushions (anisophyllous, medium and prostrate to ascending in var. submutica), light green to pure and at times shiny green (especially in shade), becoming golden brown in sun; shoots to 3 mm wide, hooked at the tip. Branching infrequent, clearly lateral in position, smaller and much shorter than the main shoot, rarely pseudo-dichotomous, the branches of Frullania type; branch half-leaf ± symmetric, triangular-ovate, undivided and tapering to a sharp apex (occasionally shallowly bilobed), cordate to auriculate at base; first branch underleaf 2–3-lobulate, deeply concave-canaliculate and with broadly recurved-revolute margins, obliquely inserted on ventral or ventral-lateral side of main axis near base of branch, closely associated with but not connate with an underleaf of main axis, their adaxial surfaces approximate. Ventral-intercalary leafy branches sporadically present; stoloniform branches abundantly produced. Stems wiry, the cortical cells firm, with evenly thickened walls, small. Leaves rigid, opposite, strongly ventrally deflexed, distinctly imbricate, covering stem in dorsal aspect, widely spreading (ca. 90°), moderately convex; leaves subvittate, 1015–1230 µm wide × 1150–1420 µm long, distinctly incubous, broadly and asymmetrically ovate, occasionally broader than long, the apex transversely to obliquely truncate, distinctly narrow, only 0.25–0.4× the width of leaf at its widest point, coarsely and ± symmetrically 3-dentate, the principal teeth broadly acute to subacuminate, the middle tooth often largest (8–15 cells wide at base), the teeth terminating in a single cell or a uniseriate row of 2–3 cells, the terminal cell tapering to a sharp, thick-walled point, the apex otherwise sharply and irregularly denticulate (leaf apex shallowly tridentate and otherwise entire in var. submutica); dorsal margin strongly ampliate, distinctly arched, extending to middle of stem to slightly beyond, cordate to auriculate at base, not decurrent, the margin entire or denticulate in distal half; ventral margin moderately curved, somewhat dilated to auriculate at base, entire or denticulate. Cells of leaf differentiated into a broad, diffuse band of enlarged rectangular cells in the median longitudinal portion of the leaf (subvittate), the cells much smaller near the margins, particularly the dorsal; median cells 20–29 µm wide × 30–41 µm long, moderately thin-walled, with straight-sided to bulging to knot-like trigones, intermediate thickenings often present; surface papillose in the distal half of leaf. Oil-bodies in the subvitta cells occupying a conspicuous portion of the cell lumen, pale smokey grey, 2–3(4) per cell, homogeneous, with various indentations, furrows and a few weak, thin, membranous segments, the segmentation irregular and uneven, with age the individual spheres swell considerably and the oil-bodies then become fewer-segmented and ultimately smooth; nonvittate cells and distal cells of lobes with oil-droplets only. Underleaves conspicuous, 3.6–4× stem width (when flattened), firm, squarrose-reflexed, deeply concave-canaliculate, resembling a scallop shell, the margins broadly recurved, the adaxial surface broadly exposed, often conspicuously connate with the leaves on both sides, ± reniform, wider than long, sometimes with a median sulcus, particularly when proximal to a branch (underleaves small, moderately spreading, hemispherical and narrowly revolute in var. submutica); apex and margins irregularly lobulate and sharply toothed like the margins of the leaves (occasionally edentate, particularly in var. submutica), without a distinct border of thin-walled, hyaline cells (or merely the teeth hyaline, or at most with an intermittent strip of hyaline cells 1(2) cells wide; median cells ± elongate-rectangular (ca. 18 µm wide and thus narrower than those of the leaves); surface papillose.
Androecia and gynoecia not seen.
Key to Varieties
Distribution and Ecology : Endemic to New Zealand: Campbell Island, Auckland Islands, Stewart Island (5–640 m), South Island (60–1340 m), North Island (670–1310 m). Known from Rakiura (Stewart Island, Muttonbird Islands), Fiordland, Southland, Westland, Canterbury (upper Wilberforce River), Otago (Mt. Cargill, Ajax Swamp, Lakes ER), Western Nelson (Arthur Ra., Marino Mtns., Paparoa Ra.), Sounds–Nelson (Richmond Ra., Mt. Stokes), Southern North Island (Ruahine and Tararua ranges), Volcanic Plateau (Tongariro Natl. Park), Taranaki (Mt. Taranaki), Gisborne (Urewera) and Auckland (Little Barrier Island, Coromandel Peninsula) EPs. Uncommon in the North Island, but widespread in the wetter parts of the South Island.
A species with a broad altitudinal range. It occurs in wet, rich forests, especially those with Nothofagus species present, from near sea level to treeline. The species occurs on bryophyte-covered old logs and rather commonly on tree bases, where it may form large masses. In particularly humid forests it forms masses on bryophyte-covered tree trunks, such as the rich, lowland forests of the Jackson River area (South Westland). The species is also terricolous, particularly where the forest floor is densely covered with bryophytes, and in such sites may form extensive patches (at times of ca. 1 m2). Also on banks covered with bryophytes or bryophytes and hymenophylls. Also present in the penalpine zone, typically over damp leaf litter under Chionochloa tussocks.
Comments : Well-developed plants of this species are the easiest of the opposite-leaved New Zealand species of Bazzania to recognize because of the large, petaliform, squarrose-reflexed underleaves, the subisophyllous condition and the erect habit of growth. The underleaf margins are not ragged, but rather very coarsely serrulate (studded with spinose teeth). In addition, the branches are obviously lateral in position (rather than pseudo-dichotomous) and are typically smaller and much shorter than the main shoot. The first branch underleaf is transversely inserted and laterally aligned with an underleaf of the main axis; the margins of both are strongly reflexed, so that their adaxial surfaces are closely approximate (“back-to-back”), but not connate. Although long associated with B. adnexa (cf. Lindenberg & Gottsche, 1851, sub Mastigobryum novae-hollandiae), the expression known as var. submutica is better understood as a variety of B. involuta, as suggested by Hodgson (1954). While it is always possible to identify this species, in particular to separate it from B. adnexa, it is more difficult to assign specimens that come from forested habitats to one or other variety. Varietysubmutica may be differentiated from the typical variety as follows:
