Solenostoma hodgsoniae
Symphyomitra grandifolia (Berggr.) Steph., Sp. Hepat. 2: 107. 1901.
Jungermannia grandifolia (Berggr.) E.A.Hodgs., Trans. Roy. Soc. New Zealand 85: 582. 1958, non J. grandifolia Hook.f. & Taylor, London J. Bot. 3: 474. 1844 (= Leptoscyphus horizontalis (Hook.) Kuhnem.).
Solenostoma hodgsoniae (Grolle) J.J.Engel, Novon 17: 312. 2007.
Lectotype (fide Váňa, 1975): New Zealand, South Is., Westland Prov., Teremakau River, between Blake’s and Kelly’s, Mar. 1874, Berggren 3140 (LD, non vidi); isolectotype: (G!).
[Plate 13F, G; Fig. 151: 1, oil-bodies, p. 696; Figs. 153, 154]
Plants mostly strongly prostrate, rarely ascending, tightly adhering to substrate and to other shoots laterally and below by abundant rhizoids and often forming tight, compact groups of several individuals or small mats, often appearing turgid and julaceous, usually bright grass-green to yellowish green, less often brownish green, often strongly tinged with clear wine-red at bases of leaves, the plants robust for genus, to 5 mm wide, the shoot tips rather abruptly turned upward. Branching infrequent, lateral-intercalary. Stems thick and fleshy, colorless to brownish green to rose-tinted, the cortex of 1 (locally 2) rows of much smaller cells; medullary cells large, thin-walled. Rhizoids long, abundant, diffuse, never in bundles, arising from the ventral side of stem and from extreme bases of leaves, colorless to yellowish, the surface indistinctly roughened. Leaves horizontally laxly spreading to more commonly dorsally assurgent, the dorsal margins (seen on edge in dorsal view) vertically oriented and mutually appressed along the median line, the leaves weakly concave, the median basal portion of the leaf concave and laxly sheathing the stem, the insertion steeply oblique to ± longitudinal for most of its length, abruptly short-recurved at ventral end; leaves 2–3-stratose in median-basal sector, orbicular to reniform (when flattened), broader than long, to 2.5–4(5) mm wide, 2–3 mm long, entire, the apex broadly rounded, the margins sometimes undulate, the dorsal moderately to distinctly decurrent, the ventral abruptly short-decurrent. Cells thin-walled, with sharply defined, small, straight-sided to bulging to at times knot-like trigones, the cells of median portion of leaf lax, short-rectangular, 38–54 µm wide × 55–78 µm long to ± inflated, 50–84(96) µm wide × 72–98(125) µm long, the cells in distal sector smaller, ± isodiametric to somewhat broader than long, (30)50–60 µm wide and long, the marginal cells 37–48 µm wide and long; surface smooth. Oil-bodies pale greyish brown, (2)3–5(7) per cell, moderately granular, the spherules not protruding beyond membrane, the oil-bodies subglobose to ovoid to elliptic. Underleaves absent. Asexual reproduction absent.
Dioecious. Androecia terminal and rosette-like, becoming intercalary; bracts very little differentiated from the leaves, broadly overlapping, in 3–6 pairs, concave, widely spreading, the antheridia often plainly visible from above, 3–4(5) per bract, the stalk polyseriate. Gynoecia terminal but appearing sessile on dorsal side of shoot, the shoot continuing growth by a stout intercalary innovation, with ca. 2–3 series of bracts that gradually merge in size and form with leaves, bracts of innermost series weakly united with the base of the perianth, the bracts broadly reniform, with a truncate apex, similar to the vegetative leaves in shape but larger; bracteole absent. Perianth not exserted beyond bracts, the summit of the beak at about the same level as the bract margin, the perianth ovate to ellipsoid, distinctly 5-plicate, abruptly constricted at the mouth, short-beaked, the mouth ± regularly crenulate by projecting cells that arch inward; cells of beak portion elongated, uniformly slightly thick-walled, those at mouth with tips often free for up to ca. 0.5 (occasionally free for greater distances), bluntly rounded at the summit; cells of the perianth proper similar to the leaf cells in form and size, with large trigones.
Seta seen only in collapsed state. Capsule irregularly splitting into ca. 6 valves, the walls carmine red, the wall 4(locally 5)-stratose, 62–67 µm thick, the outer layer a little less than subequal to the thickness of all inner layers combined; outer layer of cells subquadrate to short-rectangular, thin-walled, with prominent deep carmine to almost blackish nodule-like to short spine-like thickenings on most longitudinal walls, the transverse walls often with similar thickenings; inner layer of irregularly elongated cells, the longitudinal walls with thin, sheet-like, pigmented thickenings and narrow, often semiannular bands, the bands sporadically branched.
Spores with walls thin, very pale brown, 15.8–19.2 µm in diam., with low, delicate, fine papillae and short-vermiculate markings. Elaters tortuous, 9.6–10.6 µm wide, bispiral, the ends thick-walled and nonspiral for ca. 0.25–0.35 the elater length, the thick-walled portion ± parallel-sided and sinuous, the spirals 3.8–4.3 µm wide.
Distribution and Ecology : Endemic to New Zealand: South Island (15–1250 m). Known only from Westland and Western Nelson EPs.
Occurring on large vertical, stabilized, clayey banks at roadsides, at times at the upper extremity of the bank at the lip of forest. For example, at Cascade Road (just W of Jackson River, SW of confluence of Jackson and Arawata rivers, Westland, 45 m) it occurs on bryophyte-covered roadside banks dominated by Isotachis, with Fuchsia excorticata at the base of the bank (at the margin of a mature Nothofagus menziesii forest). Also on vertical banks along tracks, e.g., along the track to German Terrace (SSE of Westport on Nine Mile Road, 90 m) at the margin of a forest of N. truncata. At Mt. Arthur Hut Track (Kahurangi Natl. Park) occurring at 1050–1250 m over thick soil in a crevice at the side of a sinkhole in a N. menziesii forest. Exceptionally on vertical clayey banks in the penalpine zone, e.g., in an area dominated by Dracophyllum and Olearia at 1150–1170 m along the track to Alex Knob (Westland Natl. Park). Plants typically occur prostrate over soil as pure small mats or, less often, admixed among other bryophytes; shoots tightly adhere to the substrate and to other shoots of the species. It has been found with Cryptochila nigrescens, Hypnum chrysogaster, Isotachis montana, Lembidium longifolium, Lepidozia spinosissima, Pallavicinia tenuinervis, Pohlia wahlenbergii and Telaranea tetrapila.
Comments : Solenostoma hodgsoniae is a striking plant, with its broad, grass-green shoots, growing prostrate and firmly adhering to the substrate by the copiously developed rhizoids arising from the ventral side of the shoot. The leaves are broadly orbicular to reniform and overlap broadly at the shoot tips forming conspicuous, flaring rosettes. Although the plant is typically an intense green in color, the leaf bases are often rose-tinted.
Váňa (1975) treats Solenostoma hodgsoniae as a “mod. leptoderma - magnifolia ” of S. orbiculatum (p. 703), but as circumscribed here, S. orbiculatum is abundantly distinct in its smaller size, more compact leaf areolation and striolate surface. The size of S. hodgsoniae alone (shoots to 5 mm wide) distinguishes it from any other New Zealand member of the genus. See also comments under S. orbiculatum.
