Telaranea pulcherrima (Steph.) R.M.Schust.
Lepidozia pulcherrima Steph., Sp. Hepat. 3: 600. 1909.
Telaranea pulcherrima (Steph.) R.M.Schust., J. Hattori Bot. Lab. 26: 256. 1963.
Type: New Zealand, Okarito, Kirk 588 (G!, CHR 4844!).
[Fig. 66; Fig. 67: 4, oil-bodies, p. 322]
Plants subisophyllous, with a soft and woolly appearance, flexuous, prostrate, superficially appearing like Trichocolea mollissima, markedly pale green, distinctly nitid when dry; shoots medium, to 1.3 cm wide (including branches). Branching regularly and rather densely 1-pinnate, 2-pinnate in broadest portion of plant, the branches of the Frullania type; branch half-leaf 4–5(6)-lobed, cuneate, the lobes diverging; first branch underleaf 3–4-lobed, inserted on ventral-lateral side of juncture of branch and main shoot. Ventral-intercalary branches frequent, leafy, often becoming leading shoots. Stems with cortical cells poorly differentiated, in 24–30 rows of thin-walled cells, the dorsal and lateral somewhat larger than the exceedingly thin-walled medullary cells but hardly forming a differentiated hyaloderm, the 6–8 or more ventral cortical cells not or scarcely larger than medullary cells; medullary cells numerous (ca. 75), thin-walled. Rhizoids originating from basal tier of underleaf cells. Leaves soft yet firmly attached, the disc spreading, the lobes becoming suberect, the leaves closely imbricate, feebly convex due to slight decurving of lobes, the insertion subtransverse to weakly incubous; leaves 1015–1825 µm wide × 1015–1400 µm long, very slightly asymmetric, ± equally (7)9–12(13)-lobed to 0.55–0.65, the lobes ± symmetrically spreading, longer than the disc. Lobes ciliiform, widely spreading, uniseriate throughout, inserted on a triangular base composed of 2 disc cells, the uniseriate portion 6–9(10) cells long, the cells ± thin-walled, the septa somewhat thickened in the corners, moderately to distinctly constricted, the basal cell 40–66 µm wide × (110)120–140 µm long (1.7–3.3:1), the longest cells 86–130(160) µm long and 3.6–5.5(6.3):1 in var. pulcherrima, 125–160 µm long and 7.4–9.6:1 in var. mooreana, terminal cell shorter than penultimate cell, rather sharply tapering to a point. Disc ± symmetrically to slightly asymmetrically short-cuneate, 4–5 cells high in dorsal sector (including intermediate cells and paired cells at bases of lobes), 3–4 cells high in ventral sector, 18–20(24) cells broad at midpoint of disc. Cells of disc in ± regular tiers, thin-walled but not delicate, without trigones, the median disc cells large, 38–48 µm wide × 62–84 µm long; basal row of disc cells (intermediate cells) narrower; surface smooth. Oil-bodies in all cells of leaf ?except terminal cell of uniseriate row, occupying a very small portion of cell, hyaline, 5–8 per disc cell, moderately papillose, the spherules somewhat protruding beyond the membrane, the oil-bodies elliptic to more often fusiform to subcrescentic. Underleaves similar to leaves, the disc spreading to subsquarrose (the lobes erect), imbricate, symmetrically 6–10-lobed to 0.8, the lobes symmetrically spreading; disc short-cuneate, 4–5(6) cells high (median sinus), (15)19–23 cells broad in median portion, the cells in ± regular tiers; surface as in leaves. Asexual reproduction lacking.
Dioecious. Androecia either terminal on short, secondary Frullania -type branches or on short, abbreviated, ventral-intercalary subspicate branches; bracts rather closely imbricate, strongly dorsally assurgent, 3-lobed, the dorsal somewhat inflexed (and ± oriented toward shoot apex), the lobes 3–4 cells wide at base, terminating in a uniseriate row of 3–4 elongate cells; lamina with dorsal margin somewhat incurved to form a weak pocket, with a few slime papillae or small teeth (one at times large, lobuliform and inflexed); bracts monandrous; antheridial stalk biseriate; bracteolar antheridia absent. Gynoecia with bracts very small for perianth size, those of innermost series strongly concave and ± abruptly involute-tubular forming a subcucullate apex, the bracts broadly elliptic to broadly obovate; apices very shallowly and irregularly 3–4-lobulate, the lobules composed of cells similar to those of lamina, terminating in a short uniseriate cilium of 2–3 elongated cells, often with a terminal slime papilla; lamina composed of ± regularly subrectangular cells, the margins curved, the marginal cells obliquely oriented and sinuous, the free apical ends diverging and forming irregular denticulations, with slime papillae frequent; bracteoles similar in form to bracts but slightly smaller. Perianth large for plant size, terete for most of its length, trigonous and 3-plicate only near the summit, the perianth gradually tapering toward the mouth; mouth crenate-denticulate by the variably projecting, bluntly rounded, marginal cells.
Capsule (Schuster, 1969c, p. 33; 2000a, fig. 81) wall 5-stratose, the outer layer ± equal in thickness to intermediate layers; outer layer of cells in tiers, with primary cells subdivided by 3 longitudinal walls with sheet-like sinuous thickenings, the transverse walls devoid of thickenings; innermost layer of cells ± tiered, narrowly rectangular, with semiannular bands common, mostly complete.
Spores areolate. Elaters rigid, not or weakly tortuous, 8.6–10.6 µm wide, only slightly tapering toward tips, bispiral to tips, the spirals 4.3 µm wide.
Distribution and Ecology : New Zealand: Stewart Island (100–475 m), South Island (0–900 m); Australia: Tasmania (common), Victoria (rare). In New Zealand known from Fiordland (Supper Cove, Borland Burn), Southland (Awarua Bay), Westland (Haast, Mikonui River) and Western Nelson (Stockton Plateau) EPs.
In our area of sporadic distribution from Southland to Nelson; it is apparently somewhat frequent on Stewart Island, and is common in streambeds on Stockton Plateau. This species forms pure, translucent, light yellow-green to whitish green mats in very wet sites. It is associated with quiet pools and small, quiet rills or narrow creek systems where it occurs within the pools or loosely over very deep humus or sand or silt at the creek margins. The humidity is always very high in such sites, which, on Stewart Island, are in the shade of podocarp–hardwood forests of Dacrydium cupressinum and Weinmannia racemosa, with a subcanopy of Dicksonia squarrosa and Ripogonum scandens or of stunted and dense Leptospermum scoparium – Dracophyllum – Weinmannia forest 3–4 m tall. In the Haast River area the plant occurs at sea level in open swampy areas with Sphagnum and scattered Leptospermum scoparium in low areas between hummocks. At Truran Saddle (Mikonui River, Westland, 500 m) it is found under Weinmannia racemosa forest on very wet peat and tree roots, with Riccardia crassa. On Stockton Plateau, it is common along small stream margins, usually in silt or sand flood-deposited on soil banks or rocks. Among the most hygrophytic of the Telaranea species, usually confined to sites (damp rocks near water, perhaps subject to inundation, and peaty ground where submersion could occur) where never subject to drying out.
Comments : The pale yellowish green, soft-textured, rather spongy, regularly 2(3)-pinnate, plumose shoots, and the multiple leaf lobes, radiating fan-like from the disc (Fig. 66: 1–3) will immediately distinguish this species. In all these respects, the plants have the aspect of a small, delicate Trichocolea.
Two varieties of the species are recognized, one in New Zealand, the other, var. mooreana (Steph.) J.J.Engel & Merril l, in Tasmania and Victoria.