Telaranea elegans (Colenso) J.J.Engel & G.L.Merr.
Type: New Zealand, Great Barrier Is., Firth of Thames, 1888, Winkelmann (Colenso a.1355) (BM!, WELT!).
Lepidozia tripilosa Steph. in Steph. & Watts, J. Proc. Roy. Soc. N. S. W. 48: 116. 1914.
Type: Australia, New South Wales, Centennial Glen, Blackheath, 10 Jan. 1911, Watts 1043 (G!).
Plants delicate, flexuous, prostrate in loosely creeping, thin mats, faintly glaucous and water-repellent (particularly shoot tips), yellowish green to olive-green and ± nitid, becoming brownish with age; shoots medium, to 6 mm wide, including branches. Branching loosely but ± regularly and often sparingly pinnate, the branches of the Frullania type; branch half-leaf bifid, linear; first branch underleaf undivided, subulate, inserted on ventral-lateral side of branch near juncture of branch and main axis. Ventral-intercalary branches occasional, both stoloniform and leafy and becoming leading shoots. Stems with cortical cells thin-walled but firm, in 12 rows, in section much larger than the numerous (26–29) medullary cells. Rhizoids from distal cells of underleaf disc. Leaves on main shoot spreading at right angles to stem, approximate to contiguous but scarcely overlapping, plane, strongly horizontally oriented, the disc in the same plane as the dorsal surface of the stem or nearly so, the insertion almost longitudinal, the lobe tips often broken; leaves 200–285 µm wide × 385–575 µm long, longer than broad, (3)4-lobed to 0.4, the lobes strictly parallel with disc margins, shorter than the disc. Lobes setaceous, 2–3(4) cells wide at extreme base, uniseriate or biseriate in basal tier, the uniseriate portion 3–4 cells long, the lobe cells successively narrower in width (the cells scarcely tapered); cells of uniseriate portion elongate-rectangular, the walls straight-sided and not bulging. Disc ± symmetrically rectangular, parallel-sided, 5–6 cells high (from median sinus base to leaf base), 8 cells wide throughout; margins entire or finely serrulate by projecting distal ends of the marginal cells (especially the dorsal margin); ventral margin ± straight, the dorsal weakly arched. Cells of disc firm, in regular longitudinal rows, uniformly and often distinctly thick-walled, trigones none; median disc cells isodiametric to short-rectangular, 23–36 µm wide, 33–49 µm long; basal row of disc cells considerably longer and forming an obvious tier; surface with a hazy to faintly granular appearance, rarely glaucous. Underleaves much smaller than leaves, widely spreading, 4-lobed to 0.75–0.85, the lobes divergent, ciliiform, consisting of a uniseriate row of 2–3 elongated, thin- to slightly thick-walled cells, inserted on 2 disc cells, terminating in a slime papilla; disc abbreviated, 2(3) cells high, 8 cells wide. Asexual reproduction probably by broken tips of leaf lobes.
Gametangia and sporophytes not seen.
Distribution and Ecology : New Zealand: North Island ([60]290–940 m); Australia: New South Wales, Queensland.
In New Zealand known from a few stations in the northern sector of North Island (Waipoua Forest, Great Barrier Island, Coromandel Forest Park and the Kaimai Ra.). The New Zealand populations occur in Nothofagus menziesii – Griselinia littoralis forest or Leptospermum scoparium – Weinmannia silvicola – Dacrydium cupressinum short forest or (Waipoua area) Agathis australis forests with W. silvicola. At Aongatete River (Kaimai Ra.) the species occurred in a mixed D. cupressinum and Beilschmiedia tawa forest with a Cyathea understory. Plants occur in shaded, moist, protected niches, often with only marginal light, as, for example, within pockets on ± vertical stream banks. Plants for the most part are very loosely creeping, and form thin, ± pure, felt-like sheets that hardly touch the substrate. At Waikohatu Stream in Waipoua Forest the species occurs not only over soil under overhanging vertical banks well above the stream, but also, at this hyperhumid site, grows epiphytic on fronds of Trichomanes elongatum. The Waipoua plant collected by Allison formed a pure colony on very shady bare ground above a creek in the forest; the niche was “too shady for other plants” (label data).
Comments : This is an interesting species, both in its morphology and its disjunct geographical distribution. In overall aspect, leaf shape, and slender, bristle-like leaf lobes it resembles a small Telaranea tuberifera (p. 312), but the lobes in T. elegans are typically shorter, only 3–4 cells in length (Fig. 63: 2, 3) vs. (4)5–6(7) cells in T. tuberifera, and the disc cells are smaller, 36–45 × 42–55 µm vs. 41–54 × 60–74 µm in T. tuberifera. Also, in T. elegans the leaf disc is rather low, 5–6 cells high vs. 6–9(10) cells in T. tuberifera. Its most notable features are the evenly thick-walled cells of the disc and the finely serrulate disc margins (Fig. 63: 1, 2). Telaranea elegans also typically lacks the conspicuous glaucous, water-repellent surface characteristic of T. perfragilis and T. tuberifera. Typically plants of T. elegans are only faintly glaucous, most evident in the youngest portions of the plant.
