Lepidozia fugax J.J.Engel
Lepidozia fugax J.J.Engel in J.J.Engel & R.M.Schust., Fieldiana, Bot. N.S. 42: 63. f. 23. 2001.
Holotype: New Zealand, South Is., Otago/Westland Prov. boundary, Mt. Aspiring Natl. Park, summit area of Haast Pass, 570 m, Engel 18023 (F); isotype: (CHR).
Plants loosely prostrate, in pure mats, rather stiff and wiry, with spreading branches, green, distinctly nitid when dry, the shoots small, to 1.2 cm wide, including branches (shoots with rigorous branches), shoots with short branches at times only 3 mm wide. Branching nearly exclusively of Frullania type, short to rather long, irregularly 1(2)-pinnate, the primary (and secondary) branches sporadically to frequently becoming whip-like, flagelliform and microphyllous; secondary branches occasional; branch half-leaf subsymmetrical, the basal sector somewhat rounded to subcordate, 2-lobed to ca. 0.3; first branch underleaf 2–3-lobed, inserted on ventral side of branch base to the ventral-lateral side of junction of main axis and branch, in both cases the first branch underleaf ± aligned with underleaves of branch. Ventral-intercalary branching occasional, leafy. Leaves fragile and easily detached, moderately concave when dry, the dorsal lobes stiffly spreading, the tips of the ventral lobes usually incurved and not visible in dorsal view; leaves when moist often with a ragged appearance, slightly concave, contiguous to imbricate, with much of stem visible in dorsal view, 0.3–0.5 mm wide and long, distinctly spreading, the dorsal margin forming an angle with stem as much as ca. 90°, the insertion distinctly incubous; leaves variable in shape, subsymmetric to moderately asymmetric, subequally to unequally 4(5)-lobed, the leaves divided to ca. 0.3–0.5 (median sinus), the distance from dorsal sinus base to insertion greater than that from ventral sinus to insertion. Lobes acuminate, often appearing short in proportion to disc, the tips often caducous (lobes often lacking the uniseriate sector), the lobes often becoming slender and 2 cells wide for much of their length, the dorsal lobes 2–4 cells wide at the base; lobes entire, terminating in a uniseriate row of 2–4(5) at most somewhat elongated (to ca. 1.3:1) cells, the cells of uniseriate row turgid, barrel-shaped, the septa constricted, the terminal cell rounded at the tip; surface of lobes papillose. Disc moderately to distinctly asymmetric (the disc then obliquely truncate), 9–13 cells high at dorsal sinus, 6–7 cells high at ventral sinus; dorsal margin moderately ampliate, cordate at the insertion, mostly entire to sinuate, sporadically with a 1–2-celled blunt or sharp tooth; ventral margin subcordate at the insertion, entire or sometimes with a single tooth. Cells of median portion of disc with walls uniformly rather strongly thickened, trigones lacking, the cells 17–24 µm wide × 20–31 µm long, ± longitudinally elongated; cells of ampliate sector ± isodiametric; marginal cells of disc and lobes in surface view with a strongly thickened free wall (the wall often crescentic and bulging into the cell lumen), the disc cells in cross section with crescentic thickenings of the abaxial wall; disc cells in cross section with crescentic thickenings of the abaxial wall; surface of disc smooth. Underleaves inserted on 7 rows of stem cells, strongly spreading, ca. 1.5–2× stem width, broader than high, symmetrically 4-fid to ca. 0.3–0.5 (median sinus), the lobes slender, acuminate, the tips often caducous, terminating in a single cell or a uniseriate row of 2–3 cells; disc 5–7 cells high at median sinus, the margins plane, entire. Asexual reproduction by caducous tips of leaf lobes.
Plants dioecious. Androecia on inconspicuous, short, determinate, tightly spicate, cernuous ventral-intercalary branches from main shoot or submicrophyllous primary branches; bracts ventricose-cucullate, 2-lobed to ca. 0.3, the lobes acute to apiculate, the lobe tips complete; antheridial stalk biseriate. Gynoecia on abbreviated ventral-intercalary branches issuing from main stem; bracts of innermost series deeply concave, suborbicular to suboblate; apices with 4 small, rather irregular lobes, the lobes often finely and sparingly crenulate, the lobes often terminating in a uniseriate row of 2 narrowly rectangular cells or 2 laterally juxtaposed cells; lamina margin bordered by cells of variable shape, the apical or free end of marginal cells at times divergent and forming a short projection or a tooth, the margin irregularly crenate-denticulate in distal sector, the basal sector of bract margin entire except for slime papillae; bracteole similar in size and form. Perianth long and prominent, slenderly cylindrical-fusiform, slightly curved, terete below, obscurely trigonous above, distinctly and deeply 3-plicate toward mouth, the perianth gradually narrowing toward the strongly contracted, shallowly 3-lobed mouth; mouth cells rather thick-walled, papillose, at the apical end laterally free for varying lengths, the mouth thus crenate-denticulate.
Seta with 8 rows of outer cells surrounding an inner core of numerous much smaller cells. Capsule oblong, the wall 26–30 µm thick, of 3 layers; outer layer of cells with two-phase development, the longitudinal walls with sinuous, sheet-like thickenings and several large nodules alternating with those that are devoid of thickenings (or are sporadically locally thickened), the transverse walls usually devoid of thickenings or sporadically have a sheet-like thickening or an isolated nodule; innermost layer of cells narrowly rectangular, semiannular bands common, close and numerous, sometimes incomplete.
Spores 12.4–13 µm in diam., the wall brown, with coarse, sharply defined, close papillae and short-vermiculate markings. Elaters rigid, nontortuous, 8.6–9.1 µm wide, only slightly and gradually tapering toward tips, bispiral to tips, the spirals 3.4–3.8 µm wide.
Distribution and Ecology : Endemic to New Zealand: South Island (570–900 m). Known only from two collections; the type occurred on an erect, decorticated, rotted, 10-m-high tree remnant in a Nothofagus menziesii forest at 570 m (Haast Pass). A second collection was made in the upper limits of a N. menziesii forest, where it occurred mixed with Telaranea cf. tetrapila var. roseana on rotted wood at the base of a huge tree (Mt. Brewster, Mt. Aspiring Natl. Park, 900 m). Also known from the south branch of Big Gully, Ramy River, St. Arnaud, Nelson Lakes Natl. Park at 630 m. The fragmentary shoots occurred with Dicranoloma billardierei on very rotten wood/humus in mature N. fusca – N. menziesii forest with little understory but almost continuous ground tier of Blechnum discolor (leg. T. Hay, 29 Oct. 2004, AK).
Comments : The species is the only regional member of subg. Notholepidozia with caducous leaf tips (Fig. 39: 1, 3, 5), which give the plants a distinctive ragged appearance. The turgid, barrel-shaped cells of the uniseriate row and the constricted septa are responsible for the fragility of the lobes. The cells of the broken tips often have walls that have become secondarily thick-walled, rounded and papillose, following the breakage of the lobe tips.
As in Lepidozia novae-zelandiae, the abaxial cell walls of the disc and lobes are strongly thickened. These thickenings may also be viewed in a ventral aspect of the intact shoot, by focusing on the ventral margins of the lobes. In surface view, only the outer wall of the marginal cells of disc and lobes appears thickened (Fig. 39: 4).
