Zoopsis matawaia M.A.M.Renner
Zoopsis matawaia M.A.M.Renner in M.A.M.Renner, E.A.Brown and Glenny, J. Bryol. 28: 334. f. 2. 2006.
Holotype: New Zealand, South Is., Westland ED, Omoto State Forest, Kaiata Ra., Rata Tree Peak, 290 m elevation, Renner and Paul CMSAX118 bryoplot 1 (CHR 564879!); isotype: (F!).
[Plate 9I; Fig. 110: 1, oil-bodies, p. 486]
Plants soft textured, procumbent, nitid, the shoots (600)860–1050 µm wide and at least 25 mm long. Branching copious, lateral branches exclusively Frullania type, pseudo-dichotomous, predominantly from one side of the axis; ventral-intercalary branches present, giving rise to leafy shoots, rarely to microphyllous axes. Axes subterete, the cortical cells in 6 rows, inflated, the dorsal cortical cells uniformly leptodermous, 110–140 µm wide, 90–180 µm long, the 2 ventral rows consistently the smallest (= ventral merophyte); medullary cells in 7–9 rows, narrow, forming a discernible central strand (clearly visible in dorsal view of the shoot). Rhizoids present, hyaline, smooth, produced from a small distinct rhizoid initial field at the base of the underleaves, not produced at leaf bases, the tips bulbous. Leaves remote, with 1 cortical cell intervening between successive leaves on each side of axis; leaves widely spreading, equally bilobed, the postical lobe lying slightly over the antical in dorsal view; the 2 basal cells fused for ca. two thirds their length, similar in size to the dorsal cortical cells of the stem, being 105–130 µm wide × 115–175 µm long; lobes (on leaves in mature shoot sectors) consisting of a uniseriate row of 2–3 large, inflated, thin-walled, moniliform cells that are constricted at septa, the lobes readily fragmenting; lobes of embryonic leaves (visible in this state only at the shoot apex) initially with up 7–8 uniseriate rows of cells, the terminal cell not capped by a crescent-shaped hyaline papilla. Cells of leaf serially decreasing in dimensions toward the apex, the next cell 80–100 µm wide × 115–135 µm long, the third (usually apical) cell 45–55 µm wide × 70–90 µm long. Oil-bodies in cells of stem and leaf, occupying tiny fraction of and inconspicuous portion of cell lumen, scattered irregularly throughout the cell lumen, hyaline and glistening, (0)4–6(8) per cell, moderately botryoidal but (with age) becoming conspicuously botryoidal when spherules coalesce and then oil-bodies irregularly bulging, the oil-bodies rather irregular in shape, often ellipsoidal, narrowly linear, often crescentic, 2–4 × 6–9 µm. Underleaves separated by 2 pairs of ventral merophyte cells, except at Frullania -type branches, where underleaves are separated by 3 pairs of cells, bifid nearly to base, consisting of 2 basal, subisodiametric cells (often longitudinal division of 1 or both cells results in a “disc” of 3–4 laterally juxtaposed cells); lobes divergent, initially in a uniseriate row of 3–4 cells or more cells, but, like leaves, soon fragmenting and typically leaving only the 2 basal cells, though these may also be absent on mature stem sectors, the basal cells 60–70 µm wide × 90–100 µm long, typically united for 0.15 their length. Underleaves rarely to occasionally composed of 2 subisodiametric basal cells + only 2 single-celled lobes, each capped by a single obpyriform hyaline papilla. Asexual reproduction by single-celled fragments derived from the leaf lobes.
Androecia and gynoecia unknown.
Distribution and Ecology : Endemic to New Zealand: South Island (290–750 m). Known from the Westland and Western Nelson EPs between mountains east of Lake Kaniere (Mt. Brown) and the southern end of the Paparoa Ra. (Mt. Ryall) and as far east as the Haupiri River valley (Mt. Mason). Found in forests on hillslopes of Dacrydium cupressinum, Metrosideros umbellata, Weinmannia racemosa and Quintinia serrata, on inclined humic soil on the floor of tree-root caves, mostly under Metrosideros umbellata, but also known from a tree-root cave under Pseudowintera colorata and from an overhanging surface of a rotting log. The sites are characterized by low light conditions and protection from direct rainfall, and the species can form extensive pure mats. Accompanying species are Leucobryum candidum, the creeping vine Metrosideros diffusa, Psiloclada clandestina, Saccogynidium australe, Zoopsis argentea and Z. bicruris.
Comments : Zoopsis matawaia is characterized by its lack of a multicellular disc, the leaves being divided nearly to their base into 2 uniseriate lobes, with the basal pair of cells partially united. The leaves and underleaves fragment, a feature shared with Z. ceratophylla and Zoopsidella caledonica.
Zoopsis matawaia most resembles Z. leitgebiana in having patent, few-celled, succubously inserted leaves composed of a few large cells of approximately the same dimensions as the dorsal cortical cells. Also, the underleaves on mature sectors of the shoot are composed of only 2 cells that are separated nearly or completely to the base. Zoopsis matawaia is distinguished from Z. leitgebiana by its readily fragmenting leaf lobes, its symmetrically bilobed leaves, its leaves being consistently separated by one cortical stem cell, as opposed to 1–3 cortical cells and its pseudo-dichotomous, as opposed to irregularly pinnate, branching. In Z. matawaia the leaves do not consistently extend onto the dorsal stem surface, usually leaving the two rows of cortical cells entirely leaf-free.
