Trichotemnomataceae R.M.Schust.
Blepharostomataceae subfam. Trichotemnomoideae R.M.Schust., Candollea 21: 65. 1967 (1966), nom. inval.
Trichotemnomaceae R.M.Schust., J. Hattori Bot. Lab. 36: 340. 1973 (1972).
Plants strongly anisophyllous, soft and spongy, prostrate, creeping and forming loose, wool-like tufts or mats, light to yellow-green, rather small, to 2.3 mm wide. Branching sparing, irregular, usually ventral-intercalary, occasionally of Frullania type. Stems with cortex in 1(2) layers of smaller cells with slightly thickened, often light brownish walls; medullary cells with walls thin. Rhizoids sparse, commonly altogether lacking, colorless, in tight fascicles from stem at immediate base of underleaves, the tips digitate, nonseptate. Leaves loosely imbricate, strongly succubously inserted, the lines of insertion extending to stem midline dorsally, slightly recurved at ventral end, the leaves undulate-crispate, 1100–2250 µm wide × 1300–1650 µm long, asymmetrically basically 4-lobed to 0.35–0.5, but often with several accessory lobes, the lobes all incurved, the ventral lobes larger than the dorsal and gently and broadly incurved, the dorsal-most 1 or more lobes somewhat smaller and often more sharply incurved. Lobes canaliculate (at least toward base), long-attenuate to narrowly acute, gradually tapered to a terminal, caudate, often arcuate or tortuous cilium consisting of a uniseriate row of 5–8 cells, the cells of the cilium firm-walled and with projecting septa, strongly and narrowly elongated (to 8:1), the terminal cell of uniseriate row finely tapering to a sharp point and thickened at the tip; margins of lobes recurved, armed with pairs of opposing cilia oriented at ± right angles to the lobe and often ultimately curved, the cilia 2–5 cells broad at the base, the distal portion of cilia similar to that of the lobe tips, the lower armature laciniiform; sinuses between lobes sharply recurved. Disc asymmetric, highest in ventral half, the margins on each side with a few lacinia and cilia, the ventral margin reflexed. Cells of disc irregularly arranged or in partial, ill-defined tiers, oblong-hexagonal to rectangular, the walls thin, with trigones large and slightly to moderately bulging, the surface of non-ciliate portion of lobes distinctly striate-papillose, of disc distinctly long-striate, of cilia obscurely papillose (especially the distal cells). Oil-bodies in all leaf cells dimorphic: one type, 2–4 per median leaf cell, burnt orange-brown, large, coarsely granular-finely papillose, irregular in shape, often broad-elliptic, some potato-shaped, others subcrescentic, often appearing to have a rather long, longitudinal fold or pinch, 5.3–7.2(8.6) × 12–13.4 µm, a few globose and 5.8 µm in diam.; the other type in outer part of cytoplasm, hyaline, numerous per cell, ± spherical, homogeneous, smooth and much smaller (only 1–1.9 µm in diam.). Chloroplasts smaller than smooth oil-bodies. Underleaves ca. 0.5× leaf size or a little more, deeply bifid, the lobes canaliculate and with cilia and lacinia as in leaves; disc concave (ventral view), the margins on each side with a few cilia and a small, accessory lobe. Asexual reproduction lacking.
Dioecious. Androecia spicate, at times ± vermiform, small and inconspicuous, on highly abbreviated, determinate, ventral-intercalary branches that lack normal vegetative leaves; bracts in 3–7 pairs, ventricose-inflated, ± equally 4-fid, or bifid and with a lacinia on each side, the disc with cells with small trigones, the lobes abruptly becoming ciliiform distally, the cilia shorter than those of leaves and comprised of firm-walled cells with projecting septa; antheridia (1)2–3 per bract, the stalk short, 5–6 cells long, biseriate, the body with 2 irregular tiers of cells; bracteoles lacking antheridia, slightly convex (ventral view), 2(3)-lobed, the lobes entire or with a few small teeth, the disc entire. Gynoecia on short, abbreviated, ventral-intercalary branches lacking normal leaves, with 3 rings of scale-like perigynial bractlets, the bractlets each laciniate-lobulate and with each lobe or lacinia terminating in a cilium similar in form to those of the leaf lobe tips; no tubular perianth forming, but instead, a pendent, cylindrical, fleshy, pale green marsupium develops that is densely covered by colorless rhizoids. Calyptra distinct, carried down within the marsupium, the sterile archegonia remaining at extreme base and not lifted part way up the calyptra (i.e., a shoot-calyptra lacking).
Foot with elaboration of an irregular, sheet-like, haustorial collar with a scalloped free margin. Seta with 26 rows of outer cells surrounding an inner core of ca. 42 scattered cells of ± similar size. Capsule seen only in immature stage, long-ellipsoidal, the wall 30–34 µm thick, of 2 (locally 3) layers; outer layer of cells subquadrate to short-rectangular, to 1.7× size of innermost layer.
A family with one genus, Trichotemnoma, of New Zealand and Tasmania.
