BFNA Title: Tetralophozia
XX. TETRALOPHOZIA (R.M. Schuster) Schljakov, Novosti Sist. Nizsh. Rast. 13: 227. 1976 * [Greek tetra, four, and genus Lophozia, alluding to the 4-fid lateral leaves]
Chandonanthus subg. Tetralophozia R.M. Schuster, J. Hatt. Bot. Lab. 23: 206. 1960
Plants simple or sparingly branched, shoot tips often antically bent, creeping among other foliose hepatics, ascending in loose mats, or ± upright in tightly packed cushions, ocher or brown, rarely green. Stems with ventral- and lateral-intercalary branches, rarely terminally branched (Frullania-type); cell walls in transverse section ± thickened, the surface wall of the epidermis the thickest, cell size gradually increasing from periphery to center; paraphyllia lacking except for gametangia; rhizoids hyaline, few or many, dependent on habit. Lateral leaves subtransversely inserted, succubous, imbricate or contiguous, hardly different in wet and dry condition, uneven, symmetrically divided in 4 lobes to more than half leaf length; lobes triangular, canaliculate, the margins coarsely and spinosely toothed or ciliate; basal cells ± elongated, lobe cells less so, all with distinct trigones often bulging, surface verruculose; oil bodies few per cell, botryoidal. Underleaves similar to lateral leaves, but a little smaller, 2-fid, and with narrower lobes. Specialized asexual reproduction rare (known only in T. setiformis), 1--2-celled gemmae on leaf margins. Sexual condition dioicous. Androecia intercalary, exactly as wide as vegetative parts (easily overlooked), number of bracts per androecium obviously indefinite (1--20), bracts similar to lateral leaves, but less deeply divided and somewhat saccate at base, bracteoles not bearing antheridia, antheridia (1--)2(--4) per bract, white or somewhat reddish, jacket cells not clearly tiered, 1 or 2 cell rows in antheridial stalk. Gynoecia terminal on long shoots, usually with 1 ventral-intercalary innovation, bracts and bracteole hardly differentiated; perianth longly exserted, ± cylindric and often antically curved, strongly plicate, mouth lobed and ciliate. Sporophytes rather large. Seta transverse section with many homogeneous cells. Capsule black, ellipsoid, dehiscent with 4 lobes, wall layers 4, outer and innermost layer with brown nodular thickenings along the cell walls. Elaters free, 2-spiral. Spores spherical, brown.
Species 4 (2 in the flora); North America, Arctic, Europe, Asia, Africa.
SELECTED REFERENCES: Godfrey, J. D. and G. A. Godfrey, 1978. Asexual reproduction in Chandonanthus setiformis. Bryologist 81: 326--330. Laine, T. 1970. Notes on Chandonanthus Mitt. subg. Tetralophozia Schuster. Ann. Bot. Fenn. 7: 163--169. Schuster, R.M. 1966--1992. The Hepaticae and Anthocerotae of North America east of the hundredth meridian. 6 vol. (Chandonanthus in vol. 2: 241--252). Schuster, R.M. 2002. Revisionary studies of the Chandonanthoideae (Jungermanniales, Jungermanniaceae). Nova Hedwigia 74: 465--496. Urmi, E. 1983. Tetralophozia filiformis (Steph.) comb. nov. in Europa. J. Bryol. 12: 393--401.
1. Well developed shoots rarely more than 4 cm and seldom wider than 0.6 mm; lateral leaves with narrowly triangular lobes always more than twice as long as wide; lobes abaxially canaliculate, their margins abaxially recurved; fully developed perianths less than 1.5 mm ............................................................................................. 1. Tetralophozia filiformis
1. Well developed shoots often 5--10 cm and often 0.6 mm or more in width; lateral leaves with broadly triangular lobes less than twice as long as wide; lobes abaxially concave, their margins incurved towards the stem; fully developed perianths longer than 1.5 mm ..................................................................................... 2. Tetralophozia setiformis
1. Tetralophozia filiformis (Stephani) Urmi, J. Bryol. 12: 394
Chandonanthus filiformis Stephani, Sp. Hepat. 3: 645. 1909
Plants 3--20 (--40) x (0.1--)0.2--0.6(--0.9) mm, as ± dense mats or cushions, yellowish or greenish brown. Stems (50--)100--150 \um wide, with ventral or lateral intercalary branches; cells with ± thickened walls; paraphyllia lacking; rhizoids if any, in loose groups closely proximal to underleaves, hyaline. Lateral leaves mostly imbricate, uneven, sometimes spreading, (0.1--)0.2--0.5 x 0.2--0.9 mm, hand-like, very deeply divided in four lobes, sinuses dorsally protruding, antical margin often with a very large tooth; lobes narrowly ovate and acute, more than twice as long as wide, abaxially canaliculate; cells ± elongated (except for marginal ones), subbasal cells 12--24(--32) x 10--17 \um, surface verruculose, with trigones (near leaf base bulging); oil bodies 3--5 per cell. Underleaves similar to lateral leaves, 2-fid and with narrower lobes. Androecia bracts less deeply divided than lateral leaves, less dentate, antheridial stalk uniseriate, jacket cells somewhat tiered. Perianths when fully developed less than 1.5 mm. Sporophytes not seen in region of flora.
Shaded siliceous rock outcrops in the Pacific rain forest with high air humidity, often on a thin layer of rather wet soil with dead organic material, sometimes on dead wood or even epiphytic on tree bases, often admixed with Anastrophyllum minutum, Bazzania sp., Dicranum fuscescens, Diplophyllum taxifolium, and Scapania bolanderi, occasionally with Tetralophozia setiformis; low to moderate elevations (0--600 m); B.C.; Europe; Asia.
Tetralophozia filiformis shows a highly disjunctive distribution. Its American population is at a distance of 5500 km from the E-Asian ones in Siberia and of 8000 km from the European.
2. Tetralophozia setiformis (Ehrhart) Schljakov, Novosti Sist. Nizsh. Rast. 13: 228. 1976
Jungermannia setiformis Ehrhart, Hannover. Mag. 22, 8: 142. 1784; Chandonanthus setiformis (Ehrhart) Lindberg; Temnoma setiforme (Ehrhart) Howe; Tetralophozia setiformis var. alpina (Hook.) L. Söderstr.
Plants (5--)10--40(--150) x (0.2--)0.5--0.8(--1) mm, longer plants sometimes sympodial by innovations, wiry and brittle when dry, in low mats or in densely packed cushions, ocher, brown, or rarely green. Stems mostly 200 \um wide, but from 80 to 300 \um, branching lateral- and ventral-intercalary, rarely terminal; cells somewhat thickened, those of medulla porose; paraphyllia lacking (except for androecia); rhizoids if any, in loose groups closely proximal to underleaves, hyaline. Lateral leaves imbricately overlapping, very uneven, base spreading but lobes upright and parallel to the stem, deeply and symmetrically divided in four lobes, sinuses abaxially protruding, antical margin lacking a large tooth, (0.2--)0.4--0.6 mm long and (0.2--)0.5--1(--1.3) mm wide (the smaller ones with 3 or even only 2 lobes); lobes all broadly ovate and acute, less than twice as long as wide, abaxially concave but the upper margins incurved towards the stem; cells somewhat elongated subbasally, (13--)18--25(--30) x (12--)15--20(--23) \um, those of lobes ± quadrate, surface smooth or verruculose, cell walls with trigones rarely bulging; oil bodies 2--4 per cell. Underleaves transversely inserted and contiguous, symmetrical, 2-fid, and with much narower lobes. Androecia bracts similar to leaves and with transitional forms, antheridial stalk 1- or 2-seriate, jacket cells not tiered. Perianths when fully developed longer than 1.5 mm. Sporophytes rare. Seta about 10 mm, cross section with one layer of quadrate cells, homogeneous interior ca. 10 cells across. Capsule 1.2 x 1 mm. Elaters worm-like, about 120 x 10 \um, brown. Spores 15--18 \um, finely spinulose.
Capsules mature in summer. Mountain slopes in Arctic or alpine tundra and in boreal forests, scrubs or dwarf shrub heaths, rarely on ground and not often in wet places, predominantly in exposed (rather than shaded) dry or mesic sites, preferred substratum a thin soil layer of mineral material and humus on siliceous rock outcrops or boulders, often admixed with Racomitrium lanuginosum, various lichens, ten different species of Lophozia, four different Anastrophyllum species, Ptilidium ciliare, Dicranum sp., Andreaea sp. Gymnomitrion sp., and occasionally together with Tetralophozia filiformis; low to high elevations (0--2000 m); Greenland; Alta., B.C., Nfld., Nun., N.W.T., Ont., Que., Yukon; Alaska, Maine, N.H., N.Y., Vt.; Arctic; Europe; Asia.
Tetralophozia setiformis is a variable species, some of its modifications being very different from the more common form. The basal cilia often end in slime papillae. Sporophytes are extremely rare. I am aware of one single collection with young sporophytes from America (Steere 62-956). The above description is therefore based on European material I found fertile just once and with ripe capsules in Scandinavia. "Tetralophozia setiformis var. alpina", e.g., is very slender with small 3- or even 2-fid leaves. It occurs (with transition forms) within pure stands of normally grown plants or as whole populations under unfavourable conditions. I consider them in accord with Schuster (1966--1992, vol. 2, p. 251 f.) as mere modifications.