Kurzia tenax (Grev.) Grolle
Jungermannia tenax Grev., Ann. Lyceum Nat. Hist. New York 1: 277. pl. 23. 1825.
Lepidozia tenax (Grev.) Lindenb. in Gottsche, Lindenb. & Nees, Syn. Hepat. 212. 1845.
Mastigophora tenax (Grev.) Trevis., Mem. Reale Ist. Lombardo Sci. Lett. III, 4: 416. 1877.
Lembidium tenax (Grev.) Steph., Sp. Hepat. 3: 365. 1908.
Dendrolembidium tenax (Grev.) Herzog, Ark. Bot. N.S. 1: 499. 1951.
Kurzia tenax (Grev.) Grolle, Rev. Bryol. Lichénol. 32: 174. 1964 (1963).
Type: Australia, Fraser, ex herb. Kew (G!).
Plants vigorous, in tufts or in loose, caespitose masses, with a ± distinct, creeping rhizome giving rise to long, microphyllous, root-like, often ramified geotropic axes and to stiffly erect, complex, photosynthetic systems, the erect, dendroid shoot system olive-to-brownish green to light green (principal axes usually remaining green, but somewhat whitish and translucent), the branches cernuous to (particularly when dry) circinate. Branching of the aerial shoot system decompound, 2–3-pinnate, the branches normally all terminal, dendritic, formed by ± regular alternation of Frullania - and Microlepidozia -type branches; half-leaf of Frullania -type branches 2-lobed to 0.7; first branch underleaf 2–3-lobed, inserted on ventral-lateral side of branch at juncture of stem and branch. Stem below primary branches with a large-celled hyaloderm of 16–20 colorless, echlorophyllose, very large cells, not collapsing with age; medulla of 7–10 rows of thin- to weakly firm-walled cells, without a differentiated thick-walled subcortex. Leaves of aerial photosynthetic system ca. 725–750 µm wide × 625–650 µm long, broadly oblong to oblong-quadrate, transversely to feebly succubously inserted, 5–7-lobed, divided to 0.6–0.7. Lobes slender, long-acuminate, occasionally with a basal tooth, the lobes 4–6 cells wide at base, ending in a uniseriate row of (4)5–6(7) cells, the cells of uniseriate row 36–48 × 48–62(72) µm. Disc 6–8 cells high, the margins appendiculate, bearing cilia and laciniae, some tortuous or recurved; leaf bases, along the entire, almost straight line of insertion, bearing copious, crowded, finger-like cilia or appendages directed toward stem base, the appendages to 12 cells long. Leaves of primary branches somewhat simpler than those of main stems, 4–5-lobed with disc margins less ciliate-laciniate, the appendages of the leaf base fewer and less well developed; leaves of secondary axes usually simply 4-fid, subtransversely inserted and oriented, without basal appendages. Cells of disc-middle rather thick-walled, strongly chlorophyllose, small, 13–17 × 16–25 µm up to 21–25 × 23–30 µm; surface of median and upper cells strongly and closely papillose, the cells of lobes somewhat more strongly papillose; basal cells and cells of appendages smooth or striolate, appearing less chlorophyllose than median and distal cells. Oil-bodies (Schuster, 1980a) of basal cells (at least on branch leaves and some cells of the filiform appendages) minute, present in a minority of cells, 0–1(2–3) per cell, glistening and homogeneous to obscurely 2–3 segmented, ca. 2.5–3 × 3.3–4 µm; cells of lobes uniformly oil-body free. Underleaves leaf-like, ca. 0.7–0.85 as large as leaves, symmetric, usually 5–6-lobed to 0.65–0.8, the lobes narrower than on leaves, sublinear, often ending in slime papillae; disc lower than on leaves, armed at juncture with stem with a “comb” of appendages similar to those of the leaves. Asexual reproduction absent.
Androecia on abbreviated, spicate branches from bases of the erect, leading leafy axes or (sometimes) from rhizomatous leading axes. Gynoecia on short ventral-intercalary branches, isophyllous; bracts and bracteoles erect, isophyllous, lacking appendiculi, sheathing the perianth base, ovate-lanceolate, unlobed or very shallowly bilobed, formed of elongate, pellucid, leptodermous cells, the margins entire to vaguely crenulate by slightly projecting, rounded apices of the strongly elongated marginal cells; bracteoles identical to bracts. Perianth hyaline, elongate-fusiform, very slender, about 0.6–0.75 emergent, the distal portion bluntly 3-plicate; mouth gradually narrowed, lobulate, the lobes fringed with tapered, narrow (mostly 5–8:1) cells, often sigmoidal, free only at their often arcuate apices; perianth at least locally 2-stratose proximally.
Seta with 8 rows of very large epidermal cells surrounding ca. 18 rows of much smaller, internal cells. Capsule long-ovoid-cylindrical, 575–600 µm wide × 1750–1900 µm long, the wall 3-stratose, very thin (for capsule size), 28–30 µm thick, the outer layer about equal to the combined thickness of the two inner layers; outer layer of cells with two-phase development, the primary cell walls developing almost quadrate “primary cells” devoid of thickenings, longitudinally subdivided by one wall that bears sinuous-nodular thickenings forming irregular brownish sheets of radial walls; innermost layer of cells with numerous rather weak, but closely spaced, narrow and delicate semiannular bands, appearing as tangential bands in surface view.
Spores 10–12 µm in diam., yellow-brown to pale brown, the spore wall rather thin, delicately closely, vermiculate and verrucate, the vermiculae anastomosing to some extent, but not delimiting areolae. Elaters 11–12.5(13) µm in diam., rather straight and moderately thinner at the ends, bispiral, the spirals 3–4 µm wide.
Distribution and Ecology : New Zealand: Auckland Islands (15–45 m), Stewart Island (5–200 m), South Island (2–280 m); Australia: Tasmania, southeast Australia.
In the South Island only in southwestern sector, including Fiordland, Southland and Westland, with its northern limit on the Paparoa Ra. In low-lying bogs dominated by Halocarpus bidwillii and Empodisma minus, and associated often with Riccardia cochleata (Schuster, 1980a). The species has a similar ecology to Kurzia calcarata and K. helophila. On Stewart Island (Fern Gully Track) forming pure colonies on very old rotting logs and on the forest floor in a forest dominated by Fuchsia excorticata and Griselinia littoralis canopy and a Blechnum discolor understory. Also in a bryophyte-covered mass of tree roots in an open podocarp–hardwood forest including Dacrydium cupressinum and Weinmannia racemosa with a subcanopy of Dicksonia squarrosa and the woody liana Ripogonum scandens (Port Pegasus). On Awarua Bog (Southland, near sea level) it is found under Pteridium esculentum and Baumea tenax. In forest sites it is found with Bazzania adnexa, B. nitida, Kurzia hippuroides, Pyrrhobryum bifarium, Rhizogonium distichum, R. pennatum, Riccardia crassa and Telaranea tetrapila.
Comments : Kurzia tenax differs from the Tasmanian species K. dendroides in the long-acuminate leaf lobes, ending in a uniseriate row of (4)5–6(7) cells; the smaller leaf cells (20–30 × 22–36 µm vs. 36–55 × 55–75 µm in K. dendroides), clearly smaller than the elongated cells of the uniseriate lobe apices; and the more numerous appendiculi of the stem leaves.
Grolle (1964d, p. 80) placed Kurzia tenax into subg. Dendrolembidium with Megalembidium, also a dendroid genus with superficially similar organization (see also Engel and Braggins, 2005). As noted under Megalembidium, the two differ in numerous features—most obviously in the absence of a comb of appendiculi at the leaf bases in Megalembidium.
