Hyalolepidozia microphylla R.M.Schust. ex J.J.Engel
Hyalolepidozia microphylla R.M.Schust. ex J.J.Engel, Novon 17: 310. 2007.
Holotype: New Zealand, South Is., Fiordland, Hunter Mtns., Mt. Burns, 4500–5000 ft., Schuster 84-101b (herb. Schuster).
Plants soft-textured, delicate and filiform, but rather fleshy, highly nitid and glistening, light to whitish green, minute. Branching copiously produced below, uniformly intercalary, with both ventral- and lateral-intercalary branches common, the branches forming a system of ramified, creeping or geotropic, microphyllous stoloniform axes, or becoming ascending to erect and leafy, the leafy axes simple or sparingly branched. Stems with cortical cells large, inflated, thin- to slightly firm-walled, in 6(7) rows, in surface view short-oblong; medullary cells much smaller, in 8–13 rows. Rhizoids frequent, at bases of most underleaves and leaves of creeping axes, the tips often dilated and bulbous but never ramified. Main shoots with usually 4–6 cortical cells intervening between successive leaves on either side. Leaves remote, vertically oriented, at times weakly falcate, rather obliquely spreading, transverse to feebly incubous, inserted to stem midline dorsally, oblong-ovate, 120–135 µm wide × 215–250 µm long to 160–180 µm wide × 270–320 µm long; leaves bifid to 0.55–0.65, mostly subequally bifid, or, less often, the ventral lobe somewhat smaller or abbreviated and ending in a slime papilla, 3-fid leaves occasionally present, these always with an abbreviated ventral lobe terminated by a slime papilla; lobes narrowly acute, (2)3–4 cells wide at base, terminating in a single cell or a uniseriate row of 2 cells, the tip cell of lobe slightly longer than wide and weakly tapering to a rounded summit; disc 2–3.5 cells high, 6–8 cells wide. Cells of disc weakly firm-walled, 15–18 µm wide × 50–60 µm long to (18)20–26(28) µm wide × 36–67(72) µm long; surface of lobes delicately papillose at least at apices, of disc faintly striate-papillose or smooth. Underleaves variable in size and form, narrower than stem, usually less than 0.55× area of leaves (on some shoot apices to 0.85 as large), remote, 2(3)-fid, when 3-fid often with 1–2 lobes aborted, the aborted lobes consisting of 1–3(4) cells and ending in a slime papilla; disc usually 2 cells high, 6–7 cells wide.
Plants dioecious, the androecia and gynoecia often in close proximity. Androecia mostly on ascending or erect branches of limited length; bracts contiguous to imbricate, moderately larger than leaves, concave, bifid to ca. 0.4; antheridia 1 per bract, the stalk biseriate; bracteoles lacking antheridia. Gynoecia on very short lateral-intercalary branches usually without or sporadically with 1–2(3) cycles of vegetative leaves prior to bract formation; bracts of innermost series ovate to obovate, 2(3)-lobed to 0.45, the lobes terminating in 2 laterally juxtaposed cells, a single cell or a uniseriate row of 2 rather elongate cells (to 3:1), the margins entire or with a 1-celled tooth, the disc margins entire or with a low blunt tooth formed by projecting upper ends of cells; bracteoles 2-lobed, much like bracts but slightly smaller. Perianths long-exserted, linear to long-fusiform, to 2500 × 300 µm (to 8.3:1), frequently arched, terete at base but trigonous in distal 0.6 or more (at times trigonous into the basal sector), tapering to the not or weakly contracted mouth, the mouth 9-lobulate, the lobules each comprised of a tier of 3–6 laterally juxtaposed, elongate cells occasionally followed by a second tier of 2 laterally juxtaposed elongate cells, the lobules then each terminating in an elongate, firm-walled cell (20–23 × 72–100 µm) that gradually tapers to a rounded summit; perianth 6-stratose toward base.
Seta extending capsule far beyond perianth, seen only in collapsed state (the seta collapsed even when sporophyte surrounded by perianth). Capsule long-ellipsoidal to linear, the walls exceedingly delicate and easily fragmenting, 17–19 µm thick, 2-stratose, the outer layer to ca. 2× the thickness of inner layer; outer layer of cells with two-phase development, the primary walls lacking pigmented thickenings, very delicate, with exposed tangential wall thin, the cells apparently rather soon collapsing, the secondary walls with thin continuous sheets of pigmented wall material and low nodular thickenings; inner layer of cells markedly long and narrow, with continuous sheets of pigmented wall material, the radial walls with strong nodular thickenings that often feebly extend onto the outer tangential wall, with complete, rather wide, semiannular bands sometimes present.
Spores 13.4–14.4 µm in diam., the spore wall red-brown, thin, with low but sharply defined, close papillae and short, often curved, simple or at times furcate vermiform ridges that at times anastomose but do not form areolae; spore:elater diam. ratio 1–1.2:1. Elaters rather rigid, 11.5–13.4 µm wide, short, only 91–142 µm long, tapered to the tips, bispiral to tips, the spirals 3.8–4.8 µm wide, closely wound.
Key to species of Hyalolepidozia
Key
Distribution and Ecology : Endemic to New Zealand: South Island (700–920 m), North Island (1450 m).
Known from only a few sites. In Tongariro Natl. Park (Blyth Hut to Whakapapa Track) plants occurred over soil of a recess under a rock overhang at 1450 m in the alpine zone. Also over soil under partial rock cover in a rather open Leptospermum scoparium scrub forest in a serpentine area (Red Hills, Mt. Richmond Forest Park, ca. 700–920 m). Plants occur in interwoven, diffuse patches. Schuster (2000a, p. 387) stated that the species occurs in “alpine moorlands of Fiordland.”
Comments : This minute, thread-like plant differs from the type of the genus, Hyalolepidozia bicuspidata as follows:
The species can easily be confused with Paracromastigum fiordlandiae, which is rather similar in size and has nearly exclusively intercalary branches that also originate from all three rows of merophytes. Since the two may be confused, a key is provided here to distinguish them:
Paracromastigum drucei also is a minute plant with rare production of terminal branches, but that species differs from Hyalolepidozia microphylla in the brownish pigmentation (at least in exposed sun forms), the 2–3(4)-lobed leaves and the cortical cells in 9–12 rows.
The species is illustrated in Schuster (2000a, figs. 155, 156); figures show only young gynoecia. Engel 21453 (Sounds–Marlborough EP, Mt. Richmond Forest Park, Red Hills, track to Maitland Hut, 700–920 m) has mature sporophytes. Gynoecial and sporophyte characters were derived from this specimen (see also Fig. 109).
