XX. EREMONOTUS Lindberg & Kaalas ex Pearson, Hep. Brit. Isles 200. 1900 * [Greek eremos isolated, deserted, and notos dampness, alluding to the habitat]
Anomomarsupella R. M. Schuster, Nova Hedwigia 17: 78, pl. 10. 1969
Plants minute. Stems thin, in cross section with only 15--18 firm-walled cells. Lateral leaves transversely inserted, 2-lobed and concave (not plicate as often stated); cells firm-walled, a few of them (irregularly arranged) with a single very large oil body. Underleaves reduced to a slime papilla. Asexual reproduction lacking. Sexual condition dioicous. Androecia wider than vegetative parts. Gynoecia with dorsiventrally flattened perianth. Sporophytes rather massive compared with the gametophytes.
Species 1 (1 in the flora); Arctic North America, Arctic Eurasia.
Selected references: Damsholt, K. 1977: The taxonomic status of Anomomarsupella Schust., (Hepaticae). Lindbergia 4: 132. Hentschel, J., J. A. Paton, H. Schneider, and J. Heinrichs. 2007: Acceptance of Liochlaena Nees and Solenostoma Mitt., the systematic position of Eremonotus Pearsson and notes on Jungermannia L. s.l. (Jungermanniidae) based on chloroplast DNA sequence data. Pl. Syst. Evol. 268: 147--157. Schuster, R. M. 1966--1992: The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian. 6 vol. New York, London, Chicago (Anomomarsupella in vol. 3, pp. 166--170). Urmi, E. 1978: Monographische Studien an Eremonotus myriocarpus (Carring.) Pears. (Hepaticae). Bot. Jahrb. Syst., Pflanzengesch. Pflanzengeog. 99: 498--564.
1. Eremonotus myriocarpus (Carrington) Pearson, Hep. Brit. Isles 201. 1900
Jungermannia myriocarpa Carrington, in Carrington and Pearson (ed.), Hep. Brit. Exsicc. (fasc. 2) no. 96. 1879; Anomomarsupella cephalozielloides R.M. Schuster
Plants 2--8 x (0.06--)0.10--0.15(--0.16) mm, sparingly branched, loosely creeping or ascending from a stoloniform system in dense mats, from ocher or dark greenish brown to nearly black (never reddish), somewhat shiny in dry state. Stems 50--75(--80) /um wide, branching lateral intercalary from a single specialized cell in the axils of lateral leaves (Eremonotus type of branching); stems terete, in cross section with 8--10 epidermal and 7--9 central cells; few colourless rhizoids, more and irregularly arranged in the creeping system. Lateral leaves mostly well spaced, appressed or little spreading both wet and dry, concave, in situ (90--)100--160(--180) x (60--)80--120(--130) /um, 2-fid to about the middle; lobes equal, triangular and acute, their margins mostly entire; lobe cells more or less quadrate in transverse rows, the other less regular and somewhat larger, midleaf cells more or less isodiametric (8--)12--16(--20) /um, surface verruculose, walls evenly thick; oil bodies minute except for a single very large one in some irregularly arranged cells. Ventral leaves vestigial, consisting of 1 cell (a slime papilla). Androecia becoming intercalary, width more than the double of vegetative parts and somewhat dorsiventrally compressed, length and number of bracts indefinite, bracts much larger and more pigmented than vegetative leaves, 2-fid, bulbous and somewhat keeled near the insertion, bracteoles vestigial, 1 single large antheridium, whitish and nearly spherical, with short biseriate stalk, body ca. 120 /um in diameter, filling the whole venter of each bract. Gynoecia on long shoots, sometimes with 1--2 innovations; lateral leaves gradually turning into 3 much larger bracts, free from each other and canaliculate; bracteoles vestigial; perianth longly exerted, (0.4--)0.5--0.6(--0.8) x 0.3 mm, rounded at the apex, with 1 dorsal and 2 ventral folds, mouth shortly 3-lobed and ciliate; 1-layered troughout; with 3--7 archegonia and a few paraphyses. Seta often about 2 mm long and 0.14 mm wide, transverse section with exactly 8 outer and 4 somewhat smaller inner cells. Capsule black and shiny, ellipsoid, dehiscing with 4 valves, wall with 2 cell layers, outer layer with intermediate nodular, inner layer with incomplete half-ring thickenings. Spores brick-red, spheric, (12--)14--16(--18) /um, wall thin, faintly granulated; elaters free, worm-like, ca. 100 x 7 /um, mostly with 2 spirals.
Mostly on humid or wet siliceous rock along streams in sheltered places; often together with Blepharostoma trichophyllum s.l., Solenostoma pumilum s.l., Odontoschisma macounii, Anthelia julacea or Blindia acuta; low to moderate elevations (50--1100 m); Greenland; B.C.; Alaska, Wash.; Arctic Eurasia.
The distribution of Eremonotus myriocarpus in North America is poorly known, due to its nondescript habit. It has often been mixed up with small Marsupella species, but is readily distinguished from these by the lack of red pigments.