Telaranea tetradactyla (Hook.f. & Taylor) E.A.Hodgs.
Jungermannia tetradactyla Hook.f. & Taylor, London J. Bot. 3: 286. 1844 (3: 286 [sic] in errore pro 386).
Lepidozia tetradactyla (Hook.f. & Taylor) Gottsche, Lindenb. & Nees, Syn. Hepat. 213. 1845.
Mastigophora tetradactyla (Hook.f. & Taylor) Trevis., Mem. Reale Ist. Lombardo Sci. Lett. III, 4: 416. 1877.
Neolepidozia tetradactyla (Hook.f. & Taylor) Fulford & J.Taylor, Brittonia 11: 84. 1959.
Telaranea longii Paton, J. Bryol. 17: 289. f. 1. 1992.
Holotype: Scotland, Argyll, near Dunoon, foot of Glen Massan, Younger Botanic Garden, 40 m, Long 14231 (E!); isotypes: (E!, herb. Paton; NY!).
Plants delicate, flexuous yet firm, procumbent, in compact, soft, silky, felt-like mats, normally silvery- to pure green; plants small, to ca. 5 mm wide, including branches. Branching somewhat irregularly 1(2)-pinnate, the branches of the Frullania type, complanate, the branch leaves incubously inserted and shingled; branch half-leaf bifid, the lobes diverging; first branch underleaf undivided and ciliiform, inserted on ventral side of branch at juncture of branch and main axis. Ventral-intercalary branches occasional, leafy, sometimes becoming leading shoots. Stems with cortical cells distinctly differentiated, thin-walled, in 12–13 rows; cortical cells in section much larger than the numerous (ca. 18–36) medullary cells. Rhizoids often copiously produced from cells of underleaf disc. Leaves on main shoot obliquely spreading, contiguous to loosely imbricate on main stems and closely imbricate on the branches, plane to moderately convex (due to broad, slight incurving of lobes), the leaves (of main axis) with insertion weakly to distinctly incubous, the branch leaves moderately to distinctly incubously inserted and oriented; leaves 220–320 µm wide (when lobes parallel) to 390–540 µm wide (when lobes divergent) × 490–630 µm long, symmetric to weakly asymmetric, 4(6)-lobed to 0.6–0.75, the lobes longer than disc height. Lobes ciliiform, uniseriate throughout and inserted on a triangular base composed of 2–3 disc cells or, often, with a base of (2)3–4 laterally juxtaposed cells and 1(2) additional biseriate tiers between the base and uniseriate row, the uniseriate portion (5)6(7) cells long, with cells ± thin-walled, often weakly to moderately constricted at the septa; surface smooth. Disc ± symmetrically short-cuneate, (2)3–4 cells high (from median sinus base to leaf base) including paired cells at bases of lobes, 8 cells wide in 4-lobed leaves, 12 cells wide in 6-lobed leaves. Cells of disc thin-walled but firm, ± equal in thickness to those of lobe cells, trigones lacking, the largest cells (in median sector of disc) 28–41 µm wide × 48–64 µm long; basal tier of disc cells often longitudinally elongate; surface smooth. Underleaves much smaller than leaves, strongly spreading, distant, plane to slightly incurved, 4-lobed to ca. 0.8, the lobes ciliiform, the uniseriate portion formed of 3–4 somewhat elongated cells, terminating in a slime papilla; disc abbreviated, 2 cells high, 8 cells wide. Rhizoid initial cells small, subquadrate, formed from some distal cells of underleaf disc.
Plants dioecious. Androecia either terminal or intercalary on short to moderately long primary or secondary Frullania -type branches or on short, abbreviated, ventral-intercalary, spicate branches; bracts closely imbricate, dorsally assurgent, deeply concave-subcucullate, 2-lobed to ca. 0.5–0.6, the lobes acuminate to subcaudate, terminating in a uniseriate row of 4–5 somewhat elongated, thin-walled cells, the terminal cell rounded at the summit; dorsal margin of lamina somewhat dilated and incurved, crenulate and with a few slime papillae or with a 1- to several-celled, sharp tooth; bracts monandrous; antheridial stalk uniseriate; bracteolar antheridia absent. Gynoecia with bracts small for perianth size, those of innermost series concave, short-ovoid, shallowly (3)4-lobed, the 2 median lobes normally larger, the median lobes subcaudate, terminating in a uniseriate cilium of 3–4 elongated cells, with a terminal slime papilla, the lateral processes shorter, the ciliiform process consisting of a single cell or a uniseriate row of 2 cells; lamina composed of ± regularly subrectangular cells, the margins curved, with a few crenations and blunt teeth each formed by the protruding apical end of a marginal cell that is free for varying lengths, a single cell at times entirely laterally free, rarely with a tooth consisting of a uniseriate row of 2 cells, the margins thus crenate-dentate; bracteoles similar in form and size to bracts. Perianth long-emergent, terete in basal sector, obscurely trigonous and basically 3-plicate above, the perianth narrowing toward the contracted mouth; mouth fringed with 12 caudate lobes, the lobes each with a base composed of 3–5 laterally juxtaposed, moderately elongate cells and often a lateral, single-celled spinose tooth, the lobes each terminating in a cilium composed of a uniseriate row of (2)3–5 elongate, thin-walled cells, the basal 1–2 cells 11–14 µm wide × 42–76 µm long (4.1–6.3:1).
Sporophyte unknown.
Distribution and Ecology : Endemic to New Zealand: Campbell Island (100 m), Auckland Islands, Antipodes Islands, Snares Islands, Solander Island (100 m) and Muttonbird Islands, Chatham Islands (80–240 m), Stewart Island (fide Hodgson, 1956, p. 605), South Island (15–1170 m), North Island (930–1160 m); adventive in Britain, as Telaranea longii. Rather widely cited outside of our area and was previously understood to be an amphi-Pacific species; for a discussion of extraterritorial records see Engel and Merrill (2004). Known from Fiordland, Southland (Bluff), Otago (Dunedin), Westland (Haast Pass), Canterbury (Rockwood Ra.) and Gisborne (Urewera Natl. Park) EPs.
Telaranea tetradactyla, as delimited by Engel and Merrill (2004), is restricted in New Zealand to the subantarctic and southern offshore islands, the southern sector of the South Island and two stations in the North Island (both in Urewera Natl. Park).
In New Zealand the species occurs in shaded, damp, protected niches in lower- to middle-elevation forests as well as penalpine sites. For example, it occurs on rock, deep in protected niches between boulders in a stream valley with Chionochloa, Hebe and Dracophyllum near Mt. Burns (Fiordland, 1010–1170 m). Telaranea tetradactyla is not an “abundant species” as stated by Schuster (2000a, p. 216).
Both Telaranea tetradactyla and T. lindenbergii have the perianth mouth long-ciliate (Fig. 68: 7, 9); however, in T. tetradactyla and T. lindenbergii var. complanata, the cells of the uniseriate cilia are thin-walled and relatively short, at most 90 µm long (Fig. 68: 10), vs. thick-walled and 96–130 µm long in T. lindenbergii var. lindenbergii (Fig. 68: 8).
“ Telaranea trilobata ” (Schuster, Beih. Nova Hedwigia 118: 220. f. 70. 2000, nom. inval. sin. descr. lat.) was based on a specimen from New Zealand (Doubtful Sound, Schuster 52883). According to Schuster (p. 220), this plant is very close to T. tetradactyla. We have not seen the specimen.
For comments on nomenclature see Engel and Merrill (2004).
Comments : This name has previously been loosely applied to the common, widespread and weedy plant here recognized as Telaranea lindenbergii (p. 324). Telaranea tetradactyla s. str. has a more restricted distribution and is best characterized by the lax, incubously shingled stem and branch leaves (Fig. 70: 1), giving the plants a soft, silky aspect. The leaf disc is typically 3 (and often 4) cells high vs. 2 (rarely 3) cells high in T. lindenbergii. Plants of this species are rarely encountered with perianths, and in our experience, sporophytes are unknown. This is in sharp contrast to T. lindenbergii, which characteristically bears perianths (and often sporophytes), as well as androecia.
