Triandrophyllum subtrifidum (Hook.f. & Taylor) Fulford & Hatcher
Jungermannia subtrifida Hook.f. & Taylor, London J. Bot. 3: 579. 1844.
Isotachis subtrifida (Hook.f. & Taylor) Mitt. in Hook.f., Bot. Antarc. Voy. 2(2): 149. 1854.
Mastigophora subtrifida (Hook.f. & Taylor) E.A.Hodgs., Rev. Bryol. Lichénol. 18: 25. 1949.
Triandrophyllum subtrifidum (Hook.f. & Taylor) Fulford & Hatcher, Bryologist 64: 350. 1962 (1961).
Type: Tasmania, Hooker (S!).
Isotachis triloba Steph., Sp. Hepat. 3: 656. 1909.
Type: New Zealand, South Is., Westland, Otira Gorge, R. Brown (G!).
Mastigophora beckettiana Steph., Sp. Hepat. 4: 35. 1909.
Type: New Zealand, South Is., Canterbury, Waimate, May 1901, Beckett 254 (G! – c. ♂, M!, CHR 585843 ex herb. Beckett!, MPN, hb. Hodgson no. 13200, non vidi).
[Plate 2E, F; Fig. 13: 3, oil-bodies, p. 114; Fig. 16]
Plants erect, olive-green, whitish green to pale brown to yellow-brown, the tips decurved, often magenta or orange-brown tinged, 15–30 mm long; shoots 1–3.4 mm wide. Branches rather common, of ventral- and lateral-intercalary types, often stoloniform, often with a system of prostrate stolons from which arise upright leafy shoots; Frullania -type branches rare. Stems with cortex in 1 layer, the exposed cell wall distinctly thickened, but the cells of ± similar size to those of the medulla; medullary cells thin. Leaves rigid, obscurely to distinctly ventrally secund, widely spreading (often at 90° angle with stem), 1.2–1.5(1.8)× longer than wide, the insertion recurved at dorsal end, the leaves concave, weakly to distinctly asymmetrically ovate to oblong-ovate to subrectangular, 2- or occasionally 3-lobed to 0.3–0.4, 0.4–1.4 mm wide × 0.6–2 mm long; lobes unequal, the dorsal larger, the third lobe (when present) the smallest, the lobes concave (often strongly so), mostly acute, sometimes apiculate, the tip terminating in a single cell or at most a uniseriate row of 3 cells, the lobe margins entire; lamina ca. 24–32 cells from dorsal sinus base to leaf base; dorsal margin dilated at the base, ± cordate; dorsal and ventral margins of lamina often with 1(2) processes at extreme base, the processes irregular, often laciniiform to lobuliform, often hook-like, the margins otherwise usually entire. Cells with walls evenly somewhat thickened, trigones distinct, mostly small to medium, occasionally large and bulging, median cells of lamina 17–30 µm wide, 25–38 µm long; surface densely striolate-papillose. Oil-bodies hyaline, 5–6 per cell, finely botryoidal, subglobose to narrowly to broadly elliptic. Underleaves slightly smaller than leaves, widely spreading, convex (ventral view), symmetrically ovate (often narrowly so) to oblong, 2- or occasionally 3-lobed to 0.25–0.3; lobes as in leaves; lamina margins each often with a process at extreme base similar to that of leaves, the margins otherwise entire, rarely with a tooth. Fungal partner absent.
Androecia on main shoot, terminal but eventually becoming intercalary; bracts more closely imbricate than leaves, in 4–6 pairs; bracts and bracteoles similar to leaves and underleaves except less deeply lobed, the lamina distinctly ventricose, the lamina margins often with a few coarse teeth; antheridia 2–3 per bract and bracteole, the stalk long (to 20 cells long). Gynoecia sporadic, on main shoot or leading branches; bracts of innermost series much larger than leaves, erect and ensheathing perianth, ventrally secund, asymmetrically ovate, 3-lobed, the dorsal lobe the largest, the lobes as in leaves; dorsal margin of lamina with a tooth or lacinia, the ventral with a few coarse teeth; bracteoles of innermost series similar to bracts in size and shape except the bracteoles are symmetrical and less deeply lobed, the lamina margins with a small tooth or entire. Perianth not demonstrably exserted beyond bracts, narrowly ovate, the base ± cylindrical, the distal half distinctly plicate, narrowing to the 9-lobed mouth, the lobes dentate below.
Capsule (fide Hässel and Solari, 1976) spherical, the wall 4–5 stratose, the outer wall with large nodules, the inner layer with large semiannular bands.
Spores 15 µm in diam., reddish brown, with small isolated papillae, or united and then with a vermiculate aspect. Elaters bispiral.
Distribution and Ecology : Amphi-Pacific temperate, occurring on Macquarie Island, New Zealand, Tasmania, the Philippines (Kitagawa, 1981), Tristan da Cunha, South Sandwich Islands, South Georgia, Falkland Islands, southern South America, southeastern Brazil, the Andes and Central America northward to Mexico. In New Zealand the species occurs on Campbell Island, Auckland Islands, Stewart Island, South Island (70–1520 m) and North Island (375–1400 m). Known in New Zealand from Fiordland Otago, Canterbury, Westland, Western Nelson, Marlborough, Sounds–Nelson, Southern North Island, Taranaki, Volcanic Plateau and Northland EPs. Less common in the North Island than South Island, and in the South Island not recorded much east of the Main Divide. The northernmost record is from Waipoua Forest.
A species of soil and rock, usually on stream banks or riverbanks, often within the flood zone where silt accumulates, but also on slips and overhanging banks of alluvial gravels. Recorded only once as an epiphyte, on Campbell Island. Found under lowland to upper montane forest and in open well-lit sites, and associated in such sites with Breutelia pendula, Fissidens asplenioides, F. pungens, Isotachis lyallii, I. montana, Pyrrhobryum mnioides, Sematophyllum uncinatum and Symphyogyna undulata. Also, on soil under overhanging banks with Ditrichum difficile, Heteroscyphus triacanthus, Philonotis scabrifolia and Pohlia cruda. Less commonly on stream banks and in rock crevices in the alpine zone up to 1580 m, and there found with Andreaea subulata, Cryptochila grandiflora, Hepatostolonophora rotata and Herzogobryum teres.
At stream-bank sites it can be the dominant species with little competition from other bryophytes, and its success in this habitat seems to be due to its tolerance to periodic inundation by fast-flowing water and its ability to grow out of the sediment that becomes trapped among the shoots.
Comments : The species is divided by Solari (1973) into three varieties. Varietysubtrifidum is amphi-Pacific, var. trifidum (Gottsche) Solari is Andean American in distribution and var. fuscum (Steph.) Solari occurs only in southern South America. Only the typical variety occurs in New Zealand. Hodgson (1967) cites specimens of T. trifidum from eastern and central North Island, distinguished from T. subtrifidum by lower leaf and underleaf margins with numerous teeth. Hodgson found no other character distinguishing the two species but followed Fulford and Hatcher (1961) to arrive at these identifications.
The taxon is most similar to Herbertus oldfieldianus and the two Lepicolea species, with which it shares deeply bifid to 4-fid leaves and a vitta, but is usually found in quite a different habitat. Also, the plants are erect rather than pendent, shorter and not hoary. Its leaves are more patent to the stem than in those two genera, and are less densely imbricate on the stem.
Fulford (1963b) and Fulford and Hatcher (1959) state that only two kinds of branches are found in the genus: ventral-intercalary and, rarely, lateral-terminal, Frullania -type branches. Branching in Triandrophyllum is of the ventral- and lateral-intercalary types (Fig. 16: 1), both rather common, but terminal, Frullania -type branches are rare. They apparently occur only in T. subtrifidum (Fig. 16: 2).
Type plants of Mastigophora beckettiana represent a short, caespitose form of T. subtrifidum. These differ from normal ♂ plants only in the slightly smaller size, owing to the habitat (as the label states) “on hills, among grass”—in a relatively xeric site.
