Zoopsis leitgebiana (Carrington & Pearson) Bastow
Cephalozia leitgebiana Carrington & Pearson, Pap. & Proc. Roy. Soc. Tasmania 1887: 3. pl. 38. 1888 (Mar.). Zoopsis leitgebiana (Carrington & Pearson) Bastow, Pap. & Proc. Roy. Soc. Tasmania 1887: 269. 1888 (Mar.).
Type: New Zealand, Buchanan; Tasmania, Mt. Wellington, St. Crispin’s Well, Bastow; Australia, New South Wales, Balls-head Bay, Sydney, Whitelegge.
Zoopsis tenuicaulis Colenso, Trans. & Proc. New Zealand Inst. 20: 253. (May) 1888 (1887).
Type: New Zealand, North Is., East Taupo Co., base of Tongariro Mtn. Ra., 1887, Hill.
[Plate 9A; Fig. 108: 4, oil-bodies, p. 469]
Plants delicate, very soft textured, fleshy but lax, creeping, light green, rather small, to 600(635) µm wide. Branching free, remotely pinnate, the main axis tending to maintain its dominance, the branches of predominantly Frullania type; half-leaf normally consisting of a uniseriate row of 2–4 inflated cells, the basal cell notably turgid and up to 2.5× width of the next cell, the base rarely with 2 lateral juxtaposed swollen cells, and in such cases subtend a uniseriate row; ventral-intercalary vegetative branches sparing, leafy as well as geotropic and stoloniform; apices of shoots at times becoming microphyllous, whitish and flagelliform (these sometimes again becoming normal leafy shoots). Axes pellucid and soft textured, in cross section subterete to ellipsoidal, in 6 rows: formed of 4 large cortical cell rows (= lateral merophytes), the dorsal 2 rows larger, + 2 rows of smaller cells (= ventral merophytes); dorsal cortical cells in surface view usually quadrate to 5–6-angled and subisodiametric, leptodermous; medulla of ca. 12–16 rows of much smaller cells, only 13–18 µm in diam. Leaves remote to subcontiguous, normally 1.5–3(4) cortical cells intervening between successive leaves on each side of axis; leaves laterally patent to sometimes dorsally assurgent, succubously inserted, the insertion lines not extending to stem midline dorsally and defining a leaf-free strip nearly 2 cells broad. Leaves relatively small, strongly asymmetric, to 180–220 µm wide × 240–300 µm long to apex of ventral lobe, the lobes persistent; ventral lobe (4)5–8-celled (on weak shoots only 3-celled), at base formed by 2 cells, side-by-side, the lobe proper of (2)3 progressively smaller, inflated, submoniliform cells, infrequently the ventral lobe formed of 2 tiers, each of 2 cells, plus 2 single terminal cells (then 6–7-celled); dorsal lobe reduced, formed of only (2)3 progressively smaller cells; disc 3(4–5) cells wide and 1 cell high, 2 cells wide in suboptimal phases. Leaf cells lax, leptodermous, inflated, those in lobes moniliform and progressively smaller, the end cells usually minute; basal cells and cells of lobe bases 90–120 µm wide × 110–130 µm long. Oil-bodies occupying a small fraction of the cell, dull, opaque, grey, (4)5–8 per basal cell of leaf and ones above, 7–8 per cortical cell, finely and densely papillose, globose to broadly elliptic to fusiform (many short- to long-fusiform), 7 × 9 µm to 7–8.5 × 12–16 µm. Underleaves normally separated by 2–3 tiers of ventral cortical cells, vestigial: normally formed of 2 inflated, sausage-shaped cells, each 30–40 × 55–65 µm, inserted on a “disc” formed of (2)3 quadrate cells, the disc cells usually becoming subdivided, forming a cushion of 8–16 cells from which rhizoids arise; lobe cells each terminated by a small, ephemeral slime papilla. Asexual reproduction normally absent, rarely by tubers.
Dioecious. Androecia spicate, bracts in 3–5 pairs, concave, bilobed, the dorsal lobe subequal to the ventral; antheridia 1 per bract, the stalk uniseriate. Gynoecia on weak, abbreviated ventral-intercalary branches; bracts of innermost series bifid to 0.6 or sometimes 3-fid, the lobes 2(3) cells broad, sublinear, ending in a single cell or a uniseriate row of 2 cells, the margins entire or with a tooth; bracteoles similar but smaller.
Seta with 8 rows of outer cells surrounding an inner core of 10–21 rows of small cells. Capsule wall 2–3-stratose; outer layer of cells mostly subquadrate to quadrate, with imperfect two-phase development, primary cells with hyaline walls devoid of thickenings, usually divided once transversely and once vertically, the secondary walls (both longitudinal and transverse) with strong, sinuous-nodular thickenings; inner layer of cells narrowly oblong, with numerous complete semiannular bands.
Spores delicately areolate. Elaters essentially straight, bispiral to tips.
Distribution and Ecology : New Zealand: Campbell Island, Stewart Island (5 m), South Island (60–1370 m), North Island (10–1200 m), Chatham Islands; Australia: Tasmania, South Australia, Victoria, New South Wales (Meagher and Fuhrer, 2003). An abundant species throughout temperate Australasia. In New Zealand known from Southland, Otago (Dunedin), Westland, Canterbury (Porters Pass), Western Nelson, Southern North Island (Tararua Ra.), Volcanic Plateau, Taranaki, Auckland and Northland EPs.
In New Zealand ranging from Stewart Island to the northern sector of Northland (Radar Bush, WSW of Cape Reinga). Plants are frequent in deeply shaded sites, often in sheltered, humid pockets or recesses, at times occurring deep within such niches. Rather common on steep, often vertical, banks that are often associated with streams or creeks and mostly on damp clayey soils or, less often, on rock, often where sheltered by Asplenium bulbiferum, Blechnum chambersii, B. colensoi and Leptopteris superba. Also in hollows formed by exposed tree roots and in protected niches on shaded, vertical cliff faces. Also on saturated, rich, peaty soil of narrow, shallow and stagnant pools in a mixed podocarp–broadleaf forest (South Island, Lake Kaniere Scenic Reserve). This species is often associated with Lembidium nutans, which is also a pioneer on mineral soils. Other associated species are Balantiopsis diplophylla, Breutelia pendula, Categonium nitens, Chiloscyphus spiniferus, Distichophyllum pulchellum, Fissidens asplenioides, F. leptocladus, Hypnodendron arcuatum, Kurzia hippuroides, Leptophyllopsis laxus, Philonotis tenuis, Pyrrhobryum mnioides and Zoopsis argentea. It also occasionally occurs under Chionochloa tussocks in the penalpine and alpine zones, thus overlapping in habitat with Z. macrophylla.
Comments : In contrast to Zoopsis macrophylla, Z. leitgebiana is a relatively weak and slender plant. The leaves are strongly asymmetric as in Z. macrophylla, but in Z. leitgebiana the larger ventral lobe is usually formed of only 3–4 cells and the dorsal lobe of only 2–3 cells. Leaves in Z. leitgebiana on each side are separated by 1.5–3 (less often in part 4) cortical cells vs. up to 7 cells between leaves in Z. macrophylla. The underleaves are much smaller than in Z. macrophylla and are similar to species of subg. Zoopsis : vestigial, formed of 2–3 small, quadrate basal cells and 2 inflated, sausage-shaped cells constituting the 2 lobes, each terminated by a slime papilla. As shoot maturity is approached, the disc cells undergo secondary division and a small transverse “cushion” of up to 8–16 cells is formed; rhizoids originate from such “cushion” cells. Ventral merophytes typically are formed of only 2 tiers of cells, i.e., the underleaves are separated by only 4 cells vs. 7–8 cell tiers (thus 14–16 cells) that separate successive underleaves in Z. macrophylla. The stem consists of only 6 rows of cortical cells, the 2 that each belong to lateral merophytes are notably large and inflated, the 2 belonging to the ventral merophytes are much smaller. Medullary cells are minute and, in contrast to Z. macrophylla, the entire central strand is narrower in diameter than the largest dorsal cortical cell. Branching, as in Z. macrophylla, is commonly of the Frullania type, but in this species the half-leaf is typically formed of only 3 cells. The orientation of the half-leaf is also different from Z. macrophylla : it lies along the basiscopic side of the branch.
The leaf insertion is more variable than Schuster (1999a) would admit. The insertion lines of the succubously inserted leaves do not extend to the stem midline dorsally, and they delimit a leaf-free strip of, for the most part, 2 cells wide. The leaves often are articulated or inserted directly on the radial walls of the dorsal cortical cells (see Schuster, 1999a, fig. 2: 1, 8, 9) and the leaf-free strip is 2 full cells wide. Such populations often have a leaf disc 3 cells wide. However, in some populations the dorsal extremity of the leaf is inserted on the exposed dorsal-lateral face of the dorsal-most cortical cell and ca. 0.5 of the dorsal-most cortical cell is leaf-free on each side. This condition approaches that of Zoopsis macrophylla (compare Schuster 1999a, fig. 3: 9, 10 with fig. 1: 10).
Tubers were observed in Engel 20985 from Omahuta Forest Kauri Sanctuary in Northland. These are similar in appearance to the tubers found in Telaranea tasmanica (Engel and Merrill, 2004, fig. 32: 1, 2) and represent the first report of this form of asexual reproduction in the genus.
