Leiomitra lanata (Hook.) R.M.Schust.
Jungermannia lanata Hook., Musci Exot. 2: pl. 116. 1819.
Trichocolea lanata (Hook.) Nees, Naturgesch. Eur. Leberm. 3: 116. 1838.
Leiomitra lanata (Hook.) R.M.Schust., Phytologia 45: 417. 1980.
Type: New Zealand, South Is., Dusky Bay, 1791, Menzies.
[Plate 3F; Fig. 23; Fig. 24: 2, oil-bodies, p. 178]
Plants soft and distinctly woolly in appearance, prostrate, densely interwoven, clear grass green to a little yellowish green in life, dark olive-green in herb., 35–65 mm long, the shoots 1.8–3.8 mm wide, with apices somewhat swollen. Branching irregularly sympodial to pseudodichotomous (or less often distantly and irregularly 1-pinnate), the leading axis soon losing its dominance, the main shoot and branches alike in vigor, the longest branches 8–12 mm long. Stems flexuous, lacking paraphyllia. Rhizoids rather common, from stem at immediate base of underleaves, the tips often branched. Leaves widely spreading, the lobes and cilia oriented in ± the same direction as disc, the leaves closely imbricate, the insertion and orientation strongly succubous, suborbicular to subreniform, 2250–2900 µm wide × 1750–2250 µm long, divided into 5–7 non-pinnulate lobes (the lobes in ventral sector of leaf larger), each lobe ± equally 3-fid from near the base and consisting of an adaxially divergent segment and a pair of abaxially divergent segments, each segment 2–3 cells wide at base and usually 1(2) times again 3-fid, ending in ± equally divergent cilia, the ultimate cilia uniseriate throughout. Lobes caudate, the ventral 7–10 cells wide at base, the ultimate cilia tapering toward tip, the cells rather thick-walled, the septa ± thickened and dilated, the surface with fine, short striolae and papillae, the penultimate cell 14–19 µm wide, (120)130–168(186) µm long; terminal cell tapering to a sharp, often apiculate point, (7)9–12 µm wide, 108–144 µm long, thick-walled in the tip, the surface as in cells below; sinus bases plane and not reflexed, normally lacking armature. Disc clearly evident, asymmetric, 6–10 cells high (from base to highest sinuses which are in median-ventral sector of leaf), the disc lowest in vicinity of dorsal sinus base; margins of disc 1–2 ciliate or entire. Cells of disc distinctly thin-walled, in lamina middle 30–35(43) µm wide × 93–138(150) µm long; surface finely striate-papillose. Oil-bodies markedly small for cell size, hyaline and somewhat glistening, 6–16(20) per cell in median sector of disc, up to 33 per cell in cilia, finely papillose, the spherules distinctly projecting beyond membrane, subglobose to elliptic (often irregularly so), 3.4–3.8 × 6.2–8.2 µm, spherical ones 4.8–6.7 µm in diam. Underleaves in situ appearing as a mass of cilia, much smaller than leaves, narrowly connate on both sides (on one side often obscurely so by a long narrow strip), reniform, 4–6-lobed, each lobe with same basic repeated 3-fid architecture as leaves except the basal-most 3-lobed unit obscurely in two planes or in one plane, the ultimate cilia similar to those of leaves; disc 1–3 cells high. Asexual reproduction lacking. Fungal partner absent.
Androecia intercalary on main shoot or short to long branches, the bracts often somewhat smaller than leaves, transversely inserted at dorsal end, distinctly ventricose in dorsal-basal sector, the free margin of ventricose sector with simple or bifid cilia, the abaxial face of swollen sector smooth, the bracts otherwise as in leaves; antheridia large for bract size, 1–2 per bract, the stalk biseriate. Gynoecia on main shoot or leading branches, but becoming axillary or pseudolateral (through development, respectively, of 2 or 1 subfloral branches); coelocaule low, stoutly clavate, thick and fleshy below but becoming thin and ± membranous at the cap-like summit, with 4 series of bracts and bracteoles inserted on it, the bracts similar to leaves except ± symmetrical and transversely inserted, the bracteoles slightly smaller than bracts, otherwise similar to underleaves; shoot-calyptra present. Perianth rudimentary, consisting of a ring of lobed, irregularly shaped, sometimes ± plicate bracts + bracteole that range from completely free except for a low fusion on one side of bracteole to fusion of all members, the union always low, at times barely discernible.
Seta massive, 0.85 mm and 16–18 cells in diam., up to 32 mm long, with numerous (ca. 65) rows of outer, smaller cells, the internal cells gradually becoming larger toward seta middle. Capsule almost spherical, ca. 1.3–1.5 mm wide × 1.6–1.8 mm long, feebly beaked at the tip, irregularly dehiscing or dehiscing into 4 equal valves, the walls brittle, 62–79 µm thick, of 4–6 layers; outer layer of cells small, irregularly quadrate to short-rectangular, thin-walled, delicate, hyaline, with minute, knot-like thickenings on longitudinal and/or transverse walls or the cells altogether devoid of thickenings; innermost layer of cells of very irregularly oriented, various-sized cells, the radial walls with somewhat thick continuous sheets of red-brown material, with semiannular bands common, rather narrow, usually complete, rarely forked.
Spores 11.5–13 µm in diam., with low but sharply defined, close papillae and short-vermiculate markings. Elaters somewhat contorted, bluntly pointed at the ends, short, 10.1–11 µm wide, bispiral to the tips, the spirals 2.9 µm wide.
Distribution and Ecology : Endemic to New Zealand and a rather common species in rich, damp forests of Stewart Is. (0–70 m) as well as both South Island (0–460 m) and North Island (0–700 m). Known from Rakiura (Stewart Island, Solander Island), Fiordland, Southland (Bluff Hill), Otago (Otago Coast ER), Westland, Western Nelson, Southern North Island, Volcanic Plateau, Gisborne (Urewera), Auckland (west coast and Coromandel) and Northland EPs.
The species occurs in lowland tall forest, mostly of mixed podocarps (Dacrydium, Dacrycarpus, Podocarpus and Prumnopitys), Weinmannia and Nothofagus on the forest floor, rotted logs, rotted, often decorticated wood on the floor, bedrock, and in such niches it may be locally abundant and form large, pure mats. It sporadically occurs on the lower sectors of tree trunks and exposed roots. It is rarely epiphytic on tree trunks or tree-fern trunks. Accompanying species are Achrophyllum quadrifarium, Aneura alterniloba, Balantiopsis diplophylla, Categonium nitens, Cyathophorum bulbosum, Distichophyllum pulchellum, Heteroscyphus coalitis, Hymenophyton flabellatum, Metzgeria leptoneura, Nertera villosa, Plagiochila baileyana, Psiloclada clandestina, Ptychomnion aciculare, Pyrrhobryum bifarium, P. mnioides, Schistochila balfouriana, S. glaucescens, S. nobilis, Temnoma pulchellum, Thuidium furfurosum, Trichocolea hatcheri, T. mollissima, Tylimanthus saccatus and Weymouthia cochlearifolia.
Comments : The leaves of Leiomitra lanata and Castanoclobos julaceus appear superficially similar but actually are strikingly different. In C. julaceus the cilia are repeatedly dichotomously branched and stiffly diverging, the ultimate ramifications of the cilia forming a densely interwoven “surface” that lends the plant a compact, julaceous appearance, as compared with the more loosely wooly aspect of L. lanata. The leaves of L. lanata are relatively simple by comparison, with lobes equally 3-fid from near the base, and the cilia rather straight and equally spreading in all directions.
Most similar in appearance to Temnoma pulchellum, as both are highly ciliate and are found in similar habitats, occasionally together. In Leiomitra lanata, the leaf disc is obscured by the cilia, whereas in T. pulchellum it is easily visible.
