Lepidozia pumila J.J.Engel
Lepidozia pumila J.J.Engel in J.J.Engel & R.M.Schust., Fieldiana, Bot. N.S. 42: 76. f. 29. 2001.
Holotype: New Zealand, South Is., Fiordland Natl. Park, Moraine Creek, Hollyford Valley, ca. 400–650 ft., Schuster 48111a (F); isotype: (CHR).
Plants closely prostrate, flexuous, with spreading branches, green, nitid when dry, the shoots minute to small, 365–490 µm wide (leaf tip to leaf tip), to 5 mm wide, including branches. Branching nearly exclusively of Frullania type, rather short, usually irregularly and distantly pinnate to ± regularly pinnate, the primary (and secondary) branches often becoming whip-like, flagelliform and microphyllous; secondary branches occasional; branch half-leaf subsymmetrical, cordate, 2-lobed to ca. 0.3; first branch underleaf (1)2–4-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. Acromastigum -type branches (?)occasional. Ventral-intercalary branching occasional, leafy. Leaves cup-shaped (with the tips of the lobes incurved and not visible in dorsal view) to concave, contiguous, with much of stem visible in dorsal view, somewhat longer than wide, (0.25)0.4–0.5 mm long and wide, spreading, the insertion weakly to distinctly incubous; leaves usually strongly asymmetric, 4(5)-lobed, the leaves divided to ca. 0.45–0.55 (median sinus), the distance from dorsal sinus base to insertion much greater than that from ventral sinus to insertion. Lobes attenuate, somewhat apiculate, the dorsal lobes sometimes paired, the two ventral shorter and somewhat divergent from the dorsal lobes, the lobes terminating in a uniseriate row of 2–4 cells, the cells of uniseriate row ± isodiametric or slightly longer than wide, thick-walled; dorsal lobe (2)3–5 cells wide at base; surface of lobes smooth or faintly and indistinctly papillose. Disc asymmetric, obliquely truncate and deltoid, 10–12 cells high at dorsal sinus, 4–6 cells high at ventral sinus, the margins entire, the dorsal margin ± straight, abruptly cordate near the base. Cells of disc-middle evenly and distinctly thick-walled, occasionally with small trigones, 20–33 µm wide and long; median basal cells in 1 (locally 2) rows of enlarged cells; marginal cells of disc and lobes with a thickened outer wall; surface of disc smooth. Underleaves inserted on 5–6 rows of stem cells, spreading, short, broader than high, symmetrically 4-fid to ca. 0.4–0.55 (median sinus), the lobes plane, slenderly acuminate, often only 2–3 cells wide at base, entire, terminating in a uniseriate row of 3–5 cells; disc 4–5(6) cells high at median sinus, the margins plane, entire.
Plants dioecious. Androecia not seen. Gynoecia on abbreviated ventral-intercalary branches issuing from main stem; bracts of innermost series deeply concave, broadly ovate; apices 2–4-dentate-lobulate, each lobule terminating in a single cell or a uniseriate row of 2 cells; lamina margin bordered by thin to slightly thick-walled cells of variable shape and orientation, the apical or free end of marginal cells slightly divergent and forming a short projection, the margin irregularly and often sparingly crenulate; bracteole similar in size and form. Perianth rather long and prominent, slenderly cylindrical-fusiform, straight, terete below, obscurely trigonous above, distinctly and deeply 3-plicate toward mouth, the perianth gradually narrowing toward the strongly contracted, shallowly 3-lobed mouth, the lobes crenate-subdenticulate.
Seta with 8 rows of outer cells surrounding an inner core of numerous much smaller cells. Capsule oblong, the wall 38–41 µm thick, of 3 layers; outer layer of cells with two-phase development, the longitudinal walls with sinuous, sheet-like thickenings and several large nodule-like to spine-like thickenings alternating with those that are devoid of thickenings (or are rarely locally thickened), the transverse walls usually devoid of thickenings or sporadically with an isolated nodule; innermost layer of cells ± tiered, narrowly rectangular, semiannular bands common, close and numerous, sometimes incomplete.
Spores 13.9–14.9 µm in diam., the wall brown, with dense, rather coarse but low, sharply defined papillae and simple or furcate vermiculate markings. Elaters rigid, nontortuous, 7.7–9.6 µm wide, only slightly tapering toward tips, bispiral to tips, the spirals 3.4–3.8 µm wide.
Distribution and Ecology : Endemic to New Zealand: Auckland Islands, South Island (100–1525 m), North Island (ca. 400–1080 m), Chatham Islands. Known from Fiordland, Southland, Otago, Westland, Canterbury, Marlborough (Branch River), Volcanic Plateau (Tongariro Natl. Park), Taranaki (Pukeiti Bush) and Gisborne (Lake Waikaremoana) EPs.
A species occurring over a broad elevational gradient. It occurs in forests ranging from 570 m to the upper reaches of the forest and found corticolous or on shaded, moist cliff faces and boulders. It ranges up to 1370 m in the penalpine zone on rock (particularly with some soil accumulation) or in rock crevices. Occasionally in lower-elevation forests (100–200 m) over wet humus of the shaded forest floor, and then occurring with Lepidozia pendulina or on the caudex of Dicksonia squarrosa.
Comments : This smallest New Zealand member of the laevifolia group is evidently rather rare. Suboptimal expressions of Lepidozia laevifolia with poorly developed surface papillae may well be mistaken for this species. For further details, see the discussion under L. laevifolia.
A minute phenotype of the species occurs in median and upper elevations on cliff faces and boulders and forms pure, tight, compact mats of usually wire-like, upright shoots. Shoots are ca. 350–400 µm (not including branches), and leaves are minute (400–500 µm wide and long) and in dry plants quite inconspicuous. Despite their seemingly impoverished condition, these specimens bear mature perianths.
