Acrolophozia R.M.Schust.
Acrolophozia R.M.Schust., Rev. Bryol. Lichénol. 34: 259. 1966.
Type: Acrolophozia pectinata R.M.Schust.
Plants firm, loosely prostrate to, with crowding, ascending, pale green to yellowish green to yellowish brown to deep brown, medium, to 950(1250) µm wide. Branching sparse to common, the branches lateral-intercalary; geotropic, microphyllous axes lacking. Stems rather fleshy, light green to weakly brownish, the cortex not or weakly differentiated, in 1(2) layers of thick-walled, chlorophyllose cells; medullary cells leptodermous, the dorsal 3–4 strata a little larger in diameter than ventral strata. Rhizoids few, colorless, scattered. Leaves vertical, strongly, regularly and stiffly laterally spreading, contiguous to rather closely imbricate, transversely oriented, the insertion transverse dorsally, succubous ventrally, the insertion extending dorsally beyond stem midline; leaves oblong to oblong-ovate, concave, bilobed to 0.12–0.45 (2[3]-lobed in Acrolophozia fuegiana), the lobes abaxially ± concave to concave-sulcate, loosely folded over each other; lobes acute or ovate-acute, sharp or cuspidate, the margins entire; lamina margins entire, the dorsal not decurrent. Cells thin- or weakly firm-walled, with concave-sided trigones, the median cells to 12–20 µm wide × 17–24 µm long, the basal cells scarcely larger, not elongated; surface conspicuously and coarsely papillose, the papillae close to crowded, guttulate, becoming weakly to only moderately elongated toward leaf base. Oil-bodies (A. pectinata) occupying conspicuous portion of cell lumen, hyaline, 2–4(6) per median disc cell, finely papillose. Underleaves lacking the ventral merophytes 1–2 cells broad. Asexual reproduction lacking.
Autoecious. Androecia on leading shoots, rather short lateral-intercalary branches, or gynoecial innovations, terminal but soon becoming intercalary; bracts usually in 4–8 pairs, leaf-like, scarcely smaller than leaves but a little more imbricate, the base at most moderately concave, never strongly ventricose, a dorsal tooth lacking; antheridia 1–2 per bract, the stalk uniseriate. Gynoecia terminal on leading shoots or rather short lateral-intercalary branches issuing from leading shoots; bracts in 2–3 series, grading into leaves, suberect to erect, concave, bifid like leaves; bracteole usually present (?always) as a narrow lobe very broadly connate with 1 bract (the bract then appearing trifid). Perianth closely sheathed by the 2–3 pairs of imbricate bracts that collectively form a ± distinct capitulum, the perianth not or barely exceeding the innermost bracts; perianth distinct and well developed, 1-stratose, not subtended by a perigynium (or with a low ring-like one), ovoid to oblong-ovoid, bluntly 3–6-plicate distally, the sulci shallow except at perianth apex; mouth contracted, crenulate to crenulate-denticulate by moderately elongated, slightly firm-walled, hyaline cells that are free at their apices. Calyptra thin, formed entirely from archegonial venter, with unfertilized archegonia basal.
Seta short, the capsule hardly exserted, with ca. 25–26 rows of outer cells averaging slightly smaller in diameter than the many internal cell rows. Capsule spherical or nearly so, irregularly vertically dehiscing into valves of irregular shape and width, the wall 2-layered; outer layer of cells higher than the inner, irregularly subquadrate to short-rectangular, the longitudinal walls all with 1–2(3) strong but well-isolated nodular thickenings that are typically stalked and dilated distally (occasional ones extended as obscure tangential spurs), the transverse walls with 0–1(2) similar thickenings; inner layer of cells similar in size and shape, the radial walls with thickenings similar to the outer wall but considerably weaker and more often extended as spurs, rarely extended to form weakly defined, complete semiannular bands (well-formed semiannular bands lacking).
Spores yellow-brown, 10–11 µm in diam., faintly granulate-asperulate, 1.5–1.6× elater diam. Elaters 6–7 µm wide, 3-spiral, the spirals yellow-brown, narrow.
A genus with three species, all subantarctic in range. Acrolophozia fuegiana R.M.Schust. (Schuster, 1968a) is known from South Georgia (Hässel, 1980b), the Falkland Islands (685 m) and Tierra del Fuego (Cerro Garibaldi, ca. 900 m, type). Acrolophozia sulcata Hässel (Hässel, 1980b) is endemic to South Georgia, and A. pectinata occurs in our area. We agree with the remark by Schuster (2002a, p. 519) that the position of the last species in Acrolophozia requires confirmation.
Description adapted and modified from Schuster (2002a).
References: Schuster (1966c, 1996d, 2002a).
