Zoopsis macrophylla R.M.Schust.
Zoopsis macrophylla R.M.Schust., Nova Hedwigia 68: 14. f. 1: 9–14. 1999 (“Zoopsisma crophylla”).
Holotype: New Zealand, South Is., Westland, bog N of Omoeroa River, town of Franz Josef, Schuster 67-247 (herb. Schuster).
[Fig. 108: 2, 3, oil-bodies, p. 469]
Plants markedly soft-textured, lax, creeping, pale to whitish green, nitid when dry, relatively vigorous, to 1.6 mm broad. Branching freely but rather remotely 1-pinnate, the branches of Frullania type; half-leaf lanceolate, comprised of many inflated cells, 2–4 cells wide at base, followed by 1–2 biseriate tiers and a uniseriate row of 2–3 cells; ventral-intercalary stoloniform branches occasional. Stems terete, pellucid, the cortical cells in 7–8 rows: the dorsal in 2 rows of exceedingly large, inflated cells, the lateral in 2–3 rows of cells similar in size to the dorsal, the ventral in 2–3 cells rows of smaller cells; medulla of 18–25 rows of small cells; dorsal cortical cells in surface view subquadrate to short-rectangular, leptodermous. Rhizoids few on leafy axes, frequent on stolons from bases of all appendages. Leaves remote, with 4–7 cortical cells intervening between successive leaves on each side of axis; leaves succubously inserted, the insertion nearly reaching the dorsal stem midline (ca. 0.5 of dorsal-most cortical cell leaf-free on each side), the leaves relatively large, strongly asymmetrical, 500 × 250 µm to 700–725 × 350–400 µm, asymmetrically bifid to over 0.65; lobes spreading but tips often incurved, the lobe apices each terminating in a uniseriate row of submoniliform, progressively smaller, persistent cells, the tips never with a differentiated papilla, the dorsal lobe smaller, mostly 4–8-celled, uniseriate for distal 3–4 cells, the ventral lobe lanceolate, 2–4 cells wide at base × 6–9 cells long; disc 1 cell high × 4–6 cells wide. Cells of leaves very large, leptodermous, inflated, at lobe bases 70–100 × 100–130 µm; surface smooth. Oil-bodies very small in proportion to cell volume, appearing distant and isolated in cell, grey, 4–5 per leaf cell, 6 per cortical cell, coarsely papillose, subglobose to elliptic to flask-shaped. Chloroplasts large for cell size. Underleaves distinct, separated by ca. 7–9 tiers of ventral cortical cells, small to relatively large, the lobes discrete, 1–2 cells wide and 2–3 cells long, the larger underleaves 250–290 µm wide × 240–260 µm long, with disc 4 cells wide and 1–2 cells high. Asexual reproduction absent.
Dioecious. ♂ Bracts relatively few-celled, bifid, concave; antheridial 1 per bract, the stalk uniseriate. Gynoecia with bracts oblong to obtrapezoidal, bifid to 0.7, the lobes acute to short-acuminate, terminating in a single cell or a uniseriate row of 2(3) cells, the lobe margins entire or often with 1(2) small teeth composed of 1–2(3) cells; bracteoles like the bracts.
Seta with 8 rows of outer cells surrounding an inner core of 10–22 rows of much smaller cells. Capsule wall 2–3-stratose; outer layer of cells with imperfect two-phase development, the often subquadrate to quadrate primary cells with hyaline walls, usually divided once vertically and once transversely, the secondary walls with strong, sinuous-nodular thickenings; inner layer of cells with numerous semiannular bands.
Spores 10–12 µm in diam., delicately vermiculate-areolate. Elaters straight, 12–13 µm wide.
Distribution and Ecology : Endemic to New Zealand: Stewart Island (ca. 5 m), South Island (20–870 m). Known from Fiordland (Supper Cove, Wilmot Pass), Westland (Omoeroa Saddle), Canterbury (Temple Basin, upper Bealey Valley) and Western Nelson (Dolomite Point) EPs.
Mainly a bog plant. Known from only a few stations. On Stewart Island (track to Mason Bay, ca. 5 m) the species was rather common in standing, stagnant, still water in a Gleichenia dicarpa bog with Leptospermum scoparium – Dracophyllum shrubs to 1–1.5 m, the margins of water channel typically with a dense cover of Gleichenia and Empodisma minus and occasional populations of Dicranoloma. At this site the species often formed floating mats of various sizes, including one population that measured 40 × 30 cm. Type plants occurred in partial shade of Halocarpus bidwillii in a Sphagnum – Empodisma minus – Halocarpus bidwillii bog. At Arthur’s Pass, it grows in a Halocarpus bidwillii, Chionochloa rubra, Carpha alpina, Lepidothamnus laxifolius, Sphagnum cristatum tussockland bog, growing through Sphagnum cristatum. A specimen from the Wilmot Pass track was collected as a tree-fern epiphyte and a specimen from Dolomite Point, Punakaiki, was in a rock crevice under forest, suggesting that the species occupies a wider habitat.
Comments : This species is easily distinguished by the strikingly asymmetrically bifid leaves, with large, many-celled ventral lobes and reduced, few-celled dorsal lobes. The succubously inserted leaves are inserted to the stem midline dorsally and therefore a broad, leaf-free strip is lacking. The leaves are widely separated on the axis, with up to 7 cortical cells between leaves on each side of the stem. The species may be distinguished from all members of subg. Zoopsis by the lack of differentiated papillae of the leaf lobe tips. The underleaves in Z. macrophylla are well developed, with discrete lobes. The species has the best-developed central strand of any Zoopsis, with the numerous medullary cells collectively much greater in diameter than that of the largest cortical cell. Well-developed plants are freely and laxly pinnate. Frullania -type branches are developed from both sides of the main axis and the distinctive lanceolate, many-celled half-leaf is positioned in the angle between branch and stem.
